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Full text of "The geology of the Tuapeka district, Central Otago division"

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NEW ZEALAND, /Ao*' 

^eparttttenf (of 4||^ ]»] of "^ines, r\fltX 

GTEOIjOGICAIj STJ]EIVEX BHANCH. 

(P. G. MORGAN, Director.) 




BULLETIN No. 19 (New Series). 



THE GEOLOGY 



OF THE 



TUAPEKA DISTRICT, 

CENTEAL OTAGO DIVISION. 



p. MARSHALL, M.A., D.Sc, F.G.S. 



ISSUED UNDER THE AUTHORITY OP THE HON. W. D. S. MaoDONALD, MINISTER OF MfNER. 




WELLINGTON. 

BY AUTHORITY : MARCUS F. MARKS. GOVERNMENT PRINTER. 

1918. • 



LETTER OF TRANSMITTAL. 



Geological Survey Office, 

Wellington, 1st May, 1917. 
Sir,— 

I have the honour to submit herewith Bulletin No. 19 (New 

Series) of the Geological Survey Branch of the Mines Department. 

This Bulletin has been written by Dr. P. Marshall, formerly Professor 
of Geology at Otago University, and now Headmaster of Wanganui 
Collegiate School. It embodies the results obtained by the author 
during a special geological survey of the Tuapeka district made in the 
summer of 1915-16. 

It may be as well to state that the conclusions reached by 
Dr. Marshall concerning the geological ages of the various rock-series 
differ considerably from those of previous observers, and their publication 
in an official bulletin is not to be regarded as evidence of their acceptance 
by myself or other members of the New Zealand Geological Survey Staff. 

The Bulletin contains 79 pages of letterpi-ess, and is illustrated by 
a number of plates. It includes also a coloured geological map of the 
whole Tuapeka district, together with various minor maps and plans. 

I have the honour to be, 
Sir, 
Your obedient servant, 

P. G. MOEGAN, 
Director, New Zealand Geological Survey. 

Hon. W. D. S. MacDonald, 

Minister of Mines, Wellington. 



CONTENTS. 



Letter of Transmittal 



Page 
iii 



Introduction 

Area described . . 

Previous Greological Surveys 

Fauna 

Mammals 

Birds 

Reptiles 

Amphibia 

Fishes 

Insects 



Chapter I. — General Information. 



Page 

1 Flora .. 

2 Character of Land and Soil 
2 (1.) Flood-plains of Deeper Valleys 
2 (2.) Slo])es and Hillt()j)s of Country formed 

2 of Submetaniorphic Rocks 

3 (3.) Country formed of Schistose Rocks 

4 (4.) Patches of Quartz-grits and " Ce 
4 monts " 
4 Climate 
4 Literature 



Page 
5 

7 

7 



Chapter II. — Cultubk. 



Inhabitants 

Moans of Communication 
Farming Industry 
Gold-mining 

History of Gold Discovery 

" Cement " Areas 

Alluvial Diggings 



Page 
11 
11 
12 
12 
12 
13 
14 



Gold-mining — continued. 

Quartz-mining 
Antimony 
Copper 

Scheelite and Wolfram 
Mercury 



Page 

15 
15 
16 
16 
16 



Chapter III. — Sequence of Formations and Geological History. 



Sequence of Rock Formations 
Volcanic Rocks . . 



Page 
17 
19 



Periods and Directions of Folding 
Table of Geological Events 



Page 
19 
20 



Chapter IV. — Physiography. 



Mountains and Hills 




. 21 


Uplands 




. 21 


Waitahuna Heights 




. 21 


Lammerlaw Mountains 




. 22 


Details of Surface Features 




. 22 


Rivers . . 




. 24 


Molyneux River 




. 24 



Rivers — continued . 

Tuapeka River 

Waitahuna River 

Waipori River 

Basins in Stream Valleys 

Tokomairiro River 
Tokomairiro Plain 



Page 

2o 
25 
25 
26 
26 
26 



Chapter V. — Tuapeka Series. 



Introduction 
Historical Account 
Petrography 

Balclutha . . 

Stony Creek 
Progressive Metamorphism of Rocks 
Structure 
Age .. 

Chemical .Composition of the Rocks 
Economic Geology of Tuapeka Series 
Auriferous Lodes 

O.P.Q. Lode 

Canton Lode 
. Sandagger's Lode 

Nuggetv Gully Lode 

ABC Lode 

Cemetery Lode 

Bella Lode 



Page 

27 Economic Geology of Tuapeka Series — contd. 

27 Auriferous Lodes — continued. 

28 Cox's Lode 

29 Cosmopolitan and adjoining Lodes 
29 Fulton's Lode and Neighbourhood 

33 Lodes on Lammerlaw Mountains 

34 Canada and Ocean View Lodes 

35 Gabriel's Gully Lode 

36 Gray's Gully 

37 Simpson's and Burnt Creek Veins 
37 Origin of the Gold 

37 Antimony Lode, Lammerlaw Mountains 

38 Waitahuna Copper Lode 

38 Origin of the Copper 
.38 Cinnabar 

39 • Origin of the Cinnabar 
39 I Scheelite and Wolfram 
39 I Origin of the Scheelite 



Page 



39 
40 
40 
40 
41 
41 
42 
42 
42 
43 
44 
44 
44 
44 
45 
45 



VI 



Chaptee VI. — Waitahuna Seribs. 



Subdivision of Scries 


Page 
. 48 


(1.) Auriferous Conglomerate or "Cement " 


48 


Historical and General Account 


. 48 


Hluespur 


. 50 


Wothcrstoncs 


. 53 


Forsyth . . 
Waitahuna Gully . . 
Adams Flat 


. 54 
. 55 
. 56 


Glenore . . 


. 57 


The Taieri " Moraine " . . 


. 57 


Origin of the " Cement " . . 


. 58 


Chapter VII. — Ple 


Distribution 


Page 
. 65 


Waipori Quartz Gravels . . 
Origin and Age 
Economic Geology 

Mitchell's Flat . . 


. 65 
. 66 
. 66 
. 67 



(1.) Auriferous Conglomerate or "Cement" 
— continued. 

Palaeontology and Age of the "Cement" 

Economic Geology of the " Cement " . . 
(2.) Quartz-grits 

Distribution 

Relations of Quartz-grits to Cements 

Age of Quartz-grits 

Economic Geology of the Quartz-grits 
(3.) Volcanic Rocks of the Waitahuna Series 
Conditions of Deposition of Waitahuna Seiies 



Pleistocene Deposits. 



Page 
Verier Burn . . . . . . . . 67 

Gravel Terraces of Molyneux and Tuapeka 

Rivers . . . . . . . . 69 

Molviieux River Terraces . . . . 69 

Tuapeka River Terraces . . . . 69 



Page 



58 
59 
60 
60 
61 
62 
63 
63 
64 



Chapter VIII. — Recent Deposits. 



Valley Gravels . . 
Distribution . . 
Tuapeka Flat 
Havelock (or Waitahuna) Flat 



70 
70 
70 
70 



Valley Gravels — continued. 
Distribution — continued. 
German Creek Flat . . 
Surface Clays . . 



71 
71 



Index 



Page 

72 



Vll 



PLATES. 



I. View of Tuapeka Valley (T.), looking North-west towards Blue Mountains (BM). Shows 
II 
III, 



'Chinaman" Boulders (C.) in Foreground and Mature Slopes of Uplands 

A. Molyneux VaUey, near Tuapeka Mouth . . 

B. Wetherstones Flat viewed from the South 



Frontispiece 

Facing page 



A. Samples of Gold from Tuapeka District . . 

B. Nuggets of Gold from R. J. Cotton's Claim, Lammerlaw Creek, VVaipori 

IV. View of Uplands from near Trig. F, looking North towards Lawrence 

V. Fig. I. Greywacke, Balclutha. Ordinary Light 

Fig. 2. Greywacke, Balclutha. Crossed Nicols 

Fig. 3. Rock from Stony Creek. Ordinary Light 

¥ig. 4. Rock from Stony Creek. Crossed Nicols . . . . . . . . ) 

VI. Fig. 5. Rock at East Entrance to Tokomairiro Gorge. Section cut Parallel to the» 
Flattening. Ordinary Light 
Fig. 6. Same as Fig. 5, but seen b(>tween Crossed Nicols . . . . . . I 

Fig. 7. Same Rock as Figs. 5 and (i, hut Section cut at Right Angles to the Shaly Fracture 
Fig. 8. Rock from Manuka Tunnel, cut Parallel to the Shaly Fracture . . . . / 

iFig. 9. Rock from Manuka Tunnel, cut at Right Angles to the Foliation. Ordinary Light . 

Fig. 10. Same as Fig. it, but seen between Crossed Nicols 

Fig. 11. Rock at Sluice Gate between Lawrence and Bluespur, cut at Right Angles to the |- 

Foliation. Ordinary Light 
Fig. 12. Same as Fig. 11, but viewed between Crossed Nicols . . . . . . ' 

Fig. 13. Schist, Bluespur. Section cut at Right Angles to the Foliation. Ordinary Light] 

Fig. 14. Same as Fig. 13, but seen between Crossed iNicols . . . . . . I 

Fig. 15. Schist from Entrance to Lammerlaw Creek (iorge, Waipori. Section cut at] 

Right Angles to the Foliation . . . ._ . . . . . . ) 

View of Gabriel's CJully Claim, Bluespur, looking North-eas towards Surface of Fault 
plane (F.P). Unworked Cement (C). Tailings (T.) 

Slicken 



VII. 

VIIL 

IX. 
X. 

XI. 

XII. 

XIIL 
XIV. 



Gabriel's Gully Sluicing Company's Claim, Bluespur, as seen from the South-east, 
side of Fault on Right (F.P.). Tailings on Left (T.). Schist Bottom (S.B.) 

V'iew of Golden Crescent Claim, Wetherstones, showing Overthrust Fault on Left (OF) 
Unworked Cement in Centre (C). Taihngs on Right (T.). Schist Bottom (S.B. 



' Chinaman ' 
■ (Jhinaman ' 



Boulder, Tuapeka Valley 
Boulder, Tuapeka Valley 



Quartz Gravels in Deep Lead of Verter Burn or Post Office Creek 

View looking North from Head of V'erter Burn. Tunnelling in Deep Lead (D.L.). 
Rest of Country Schist Rock (S.). Note Mature Erosion of Surface 



All the 



16 
24 

28 
32 

36. 

30 

48 

48 

.54 
00 
08 

68 



MAPS AND PLANS. 



Page 

1. Map of Central Otago Division, showing Survey Districts and Area geologically surveyed [Facing 1 

2. Map of Tuapeka District, showing Direction of Normal Fault-lines and Thrust-planes . . 23 

3. Map of VVaipori Districf, showing Reefs . . . . . . . . [Facing 40 

4. Plan of Bluespur Workings . . . . . . . . . . . . . . . . 51 

5. Plan of Waitahuna Gully Workings . . . . . . . . . . 56 

6. Sketch-map of Glenore and Adams iFlat . . . . . . . . . . . . 56 

7. Map showing Deep Lead in Valley of Post Office Creek, Waipori Survey District . . . . 68 

8. Geological Map of Tuapeka District, comprising Tuapeka East, Table Hill, and Parts of Wai- 

tahuna West and Waitahuna East Survey Districts . . . . . . . . At end. 



BuUNi? 19. 



MAP OF 

CENTRAL OTAGO DIVISION 

SHOWING SURVEY DISTRICTS 



Districts dealt yvilh 
in BuUjptuv N^ 19 



Dislricts dealt ni£hj 
in, previous huJZcfin. 







A^ 



^ 
\ 



Dunedin 



Tateri Rzver 



BULLETIN No. 19 (NEW SERIES). 



THE GEOLOGY 



TUAPEKA DISTEICT 

CENTRAL OTAGO DIVISION. 



CHAPTER I. 



GENERAL INFORMATION. 







Page 


Page 


Introduct ion . . 


.. 1 


Flora .. .. .. ..5 


Area described 


.. 2 


Character of Land and Soil . . . . 7 


Previous Geological Surveys 


.. 2 


(1.) Flood-plains of Deeper Valleys .. 7 


Fauna. 




2 


(2.) Slopes and Hilltops of Country 


Mammals . 




'. '..2 


formed of Submetamorphio Rocks 7 


Birds 




.. 3 


(3.) Country formed of Scliistose Rocks 7 


Reptiles 




.. 4 


(4.) Patches of Quartz-grits and " Ce- 


Amphibia . 




.. 4 


ments " . . . . . . 7 


Fishes 




.. 4 


Climate . . . . . . 8 


Insects 




.. 4 


Literature . . . . . . . 8 






Introd 


UCTION. 



The area that is dealt with in the present publication is that which contains the 
famous Tuapeka goldfields. It is a portion of the Central Otago Division, and covers 
the survey districts of Tuapeka East, Tuapeka West, Waitahuna East, Table Hill, 
Waipori, and a portion of Tokomairiro. The total area comprised within these survey 
districts is about 500 square miles. The maps of the Lands and Survey Department 
already contain practically the whole of the topographical features of the district, 
consequently the work was very light compared with that which the Geological 
Survey has found to be necessary in the greater number of the districts which have 
been subjected to examination since the reorganization of the Survey took place in 
1905. 

The work was commenced on the 1st November, 1915, and was continued until 
the 7th March, 1916, with the exception of three weeks in January. During this 
period the writer was assisted by Mr. G. E. Hyde. Much and valued assistance 
was obtained from the local miners' associations and from the residents of the Tuapeka 
district. They supplied much local information, and gave most valuable help in locating 
the various mineral deposits. 
1 — Tuapeka. 



Area described. 

The area is bounded on the west by the Molyneux River, on the south by the 
watershed of the Tokomairiro River, on the north by the Lammerlaw Mountains, 
extending thence to the head of Post Office Creek, and from thence through Waipori 
Falls to Milton. The excellence of the maps supplied by the Survey Office made 
it possible to traverse the district readily, with a full knowledge of the difficulties 
that would be encountered in any route and of the time that would be occupied 
in reaching any objective. The district is also well roaded, there are no mountains 
of any height, and there is an absence of forest-covered country. It was therefore 
found to be possible to visit almost any portion of the area on foot or on bicycle 
from headquarters established in the large centres such as Lawrence, Waipori, and 
Milton. Where necessary, points could easily be fixed by compass cross-bearings from 
the numerous trig, stations in the district, though the details of the plans supplied 
were such that it was in nearly every case found to be possible to locate rock-outcrops 
without reference to the trig, stations. 

Previous Geological Surveys. 

L. 0. Beal* in 1870 refers several times to the " cements " of the Tuapeka, and 
generally ascribes their origin to glacial action. Although the district had been traversed 
from time to time as a goldfields area, it seems that no attempt at a general geological 
examination was made before 1875, when Hutton's "' Geology of Otago " appeared. 
In this work there is a separate description of the Bluespur conglomerate, with an 
account of its origin as well as a general account of the geology of the surroimding 
district. Li the same work several of the metalliferous veins and alluvial deposits have 
detailed descriptions by G. H. F. Ulrich. 

In 1878 the district was visited by Cox,f who had definite and comprehensive 
instructions from Hector. He classified the older rocks of the district, and described 
roughly the areas, value, and quantities of the different deposits of conglomerate 
(cement). He regards the " cements " as deposited by a glacier travelling from north- 
west to south-east. This opinion appears to have been endorsed by Hector,{ writing 
in the progress report of the same year. 

Fauna. 

The poverty of the indigenous terrestrial animals of New Zealand is proverbial, 
and in this district is perhaps more noticeable than in most parts of the country. 
The poverty in general is doubtless due to the isolation of the country ; and though 
this isolation has not been quite continuous in the past it has certainly been of great 
length, and since the last period when the land was connected with othei* terrestrial 
regions it has been reduced at least once to relatively small dimensions. 

Mammals. 

No indigenous mammals were seen during the examination of this district, and 
it is doubtful whether any occur at the present time. Litroduced mammals are, 
however, quite abmidant. In addition to the ordinary domesticated mammals, upon the 
use and products of which the industries of this district largely depend, rabbits are 
extremely numerous in parts of the district, particularly near the larger settlements. 

* Beal, L. 0. : " On the Disposition of the AUuvial Deposits of the Otago Goldfields." Trans. N.Z. 
Inst., vol. iii, 1871, p. 270. 

fCox, S. H. : "The Tuapeka Cements." Rep. Geol. Explor. during 1878-79, No. 12, 1879, p. 42. 
X Hector, J. : Prog. Rep. in Rep. Geol. Explor. during 1878-79, No. 12, 1879, p. 25. 



Until the last few years these rodents abounded over the whole of the district, but 
at the present time they have almost disappeared from much of the higher country. 
Thus along the greater part of the road from Lawrence to Waipori no rabbits are 
to be seen at the present time. This extraordinary change is certainly due to more 
than one cause. Some of the residents maintain that extensive and systematic poisoning, 
especially during exceptionally dry seasons, initiated the decline. All agree that the 
weasels and stoats which have been introduced, and have now increased in large numbers, 
are mainly responsible for the diminution of the pest, and that as time goes on the 
rabbits become less and less numerous. Their abundance near the larger settle- 
ments is said to be due to the trapping in these localities, by which the weasels suffer 
comparatively more than the rabbits, and to shooting, for the tendency generally 
exists to shoot a weasel if oppoitunity offers. 

Of other introduced mammals the grey rat and the mouse appear to be numerous. 
Wild cats seem to be rare, and wild pigs are practically extinct. The deer, which 
are abundant in the Blue Mountains on the south-west side of the MolJ^leux River, 
have rarely been found on the eastern or Tuapeka side. 

Birds. 

In this group of fauna again indigenous species are quite unusual. In the early 
days of settlement it was othei-wise. The weka (Ocydromus mistralis) was then abundant 
over the greater part of the district, but apparently it disappeared many years ago, 
and no specimen was seen duiiiig the progress of this survey. This is lemarkable when 
it is recalled that in the pastoral districts of Canterbury this species is still frequent. 
The disappearance of the weka is, however, general throughout all those parts of Otago 
which lie to the east of the lake district. 

Another bird once numerous, at least in the patches of forest formerly fovmd 
at the heads of many of the gullies, is the kaka {Nestor meridionalis), which used 
to visit the grass country in large numbers when the berry of the Gaidlheria rupestris 
(snowberry, or so-called " nardoo " berry of Waipori) was ripe. The red-fronted or 
green parrakeet (C yanorhainphus novcs-zealandice) was also fairly common. 

The grey duck {A)tas superciliosa) is said to have been abundant, and specimens are 
still to be found in many of the creeks. The blue duck {HymenolcBmus malacorhynchus) 
was also once very common in the various momitain - streams, but this interesting 
duck, which has its only close relative in Peru, is now perhaps extinct in this 
district. The black teal {Fidigula novcB-zealandice) is also said to have been abundant. 
The well-known paradise duck {Casarca variegata) was also fairly plentiful on the 
swampy flats and on the Lammerlaw Mountains. In the swamps the pukeko. or 
swamp-hen {Porphyrio melanotus), was common, but it is now never seen. 

Shags are still found occasionally in many of the stream-valleys, the commonest 
species being the black shag (Phalacrocorax carbo). The large seagull (Larus domini- 
canus) is quite common ; sometimes it follows the plough in large numbers in the 
cultivated areas. Several were seen flying about the crags of the lower gorge of the 
Waitahuna River, whore apparently nests have been built ; others were seen on the 
dredged gravel-flat of the Waipoii River and on the rocky crags on the slopes of the 
Lammerlaw Mountains. The dotterel (Octhodromxs bicinctus) is common everywhere on 
sandy and gravelly flats, and occasionally numbers of the tern {Sterna albistriata ?) were 
to be seen on the Waipori Flat. 

The large hariier-hawk {Circus gouldi) is extremely common all over the district. 
It preys largely on the rabbits as well as on the small introduced birds, which are 
excessively common. The sparrow-hawk {Nesierax australis), however, was not noticed. 
1* — Tuapeka. 



It appears that the harrier-hawk has increased in numbers since the early settlement 
of this district. 

There are very few small birds of indigenous orioin to be seen in the district. The 
white-eye {Zosterops ccerulescens) was occasionally found in large flocks. The ground- 
lark {Anthus novcB-zelandice) is quite common. The fantail {Rhipidura fuliginosa) was seen 
in the wooded districts only. The tomtit (Petroeca macrocephala) was only rarely 
seen, and the green or bush wren (Xenieus longipes) was not seen more than once 
or twice. In the few wooded districts, such as the gorge of the Molyneux and the 
upper valley of the Tuapeka, the beautiful notes of the now rare bell-bird (Anthornis 
melanura) were heard. Is is said that the pigeon {Hemipkaga novce-zdandioB) was 
once abundant in the patches of bush throughout the district, but none is to be 
seen now. 

The red-bill, or oyster-catcher {HcBtnatopus sp.), is said to have been numerous, 
but it is now extinct throughout this district. 

The introduced birds are numerous in individuals, though not in kinds. The 
sparrow is abundant ; and the thrush, blackbird, finches, and linnets occur all over 
the area, though they are more abundant near the larger settlements. 

Reptiles. 

As elsewhere in New Zealand, members of this family are found in small numbers 
only. On the dry rocky ground the ordinary grey lizard (Lygosoma moco) is common, 
but no other reptiles were seen. 

Amphibia. 

No indigenous members of this class are known to occur within the Tuapeka 
district. Near Lawrence the pools left in the dredging and alluvial grounds are 
inhabited by large numbers of the green Australian frog. 

Fishes. 

Fresh-water fish are known to be rare in New Zealand, and in the Tuapeka 
district there is no indigenous fish of importance except the eel. This fish, however, 
is not fomid in the Waipori basin, doubtless because this river after leaving the 
lowlands of the Taieri Plain passes over falls of considerable height that form an 
effectual barrier to the upward migration of the young eels from the sea. The 
mountain " trout " (Galaxias fasdatus ?) and other species of this genus occur in some 
numbers, and the minnow {Galaxias aitenuatus) is quite common. Introduced trout 
have a wide distribution within the district, and at Waipori fish that weighed 14 lb. 
have been caught. 

Insects. 

Members of this class are scarcer than is usual in New Zealand. Only a few 
species of butterflies and moths are at all commonly seen. Various species ot blow- 
flies, including the large blue Calliphora quadrimaculata and the orange-coloured 
Bothrophora zelehori, are common. A few of the native solitary bees were seen, and 
there are many kinds of ants, while the honey-bee and the humble-bee now occur 
in considerable numbers. Of beetles, only the large bluish-black groimd-beetle and a 
tiger-beetle are commonly seen. It is surprising to find that in this grassy country 
Orthoptera are quite im usual, even grasshoppers not being common. Dragon-flies and 
mayflies are fairly abundant. Only small species of cicada were seen, and these 
but rarely. 



Flora. 
As compared with the fauna the vegetation of this district, so far as the greater 
part of the area is concerned, contains a much more varied assortment of indigenous 
species, and over large areas there are very few kinds of introduced plants. 

The forest areas are small, and are in fact restricted to the deep gorges of the 
larger streams and rivers. By far the largest area of forest lies in the gorge of the 
Molyneux River, between Tuapeka Mouth and Beaumont. The river-bed is about 
1,000ft. below the level of the comitry lying to the east; and since the ground rises 
rapidly and the forest is restricted to the lower declivities of the valley it does not 
extend beyond half a mile from the river-bank. Elsewhere small patche.s of forest 
are found in the upper portion of the valley of Nardoo Creek, Tuapeka River, of 
Gabriel's Gully aud Munro's Gul'y, and to a slight extent in the Lammerlaw Creek. 

The forest-trees are almo.st exclusively the so-called white birch or beech {Fagus 
diffortimdes) and totara {Podocarpus totara). There are few large trees, and the timber 
requirements of the district for fencing and building cannot be met locally. 

Even within the period of settlement the forest areas have been considerably 
reduced, for during times of drought the beech forest burns readily ; and the practice 
prevailed in the early days of setting fire to the high grass and scrub vegetation 
somewhat indiscriminately, without making any provision to prevent the spread of 
the fires. Before the period of settlement the forest appears to have been much 
more extensive. This is indicated by the frequent occurrence of partially decayed 
trunks of tr^es, which are said to have been found in large numbers on portions of 
the area now covered by native grasse.s. Over much of the area also small moruids, 
generally containing fragments of wood and charcoal, occur within distances of 30 or 
40 yards. It appears that these mounds have been formed by the fall of forest-trees, 
the roots of which, as the trees fell, tore up large masses of soil, as commonly happens 
in the forest-covered areas of New Zealand. There is a well-known Maori tradition 
of an extensive fire over a great portion of the South Island, which is said to have 
been started soon after the arrival of the Maori immigrants. At the present time but 
little of the Tuapeka district is covered with indigenous shrubs or " scrub." This 
was not abundant even in the early days of settlement, though the quantity of small 
wood that is fomid in the gullies during hydraulic operations shows clearly that at 
one time this type of vegetation was wide-spread. One is surprised by the almost 
complete absence of the shrubby Veronicas on the hill-slopes, and even the Cassinia 
is abundant here and there only. The tutu {Coriaria ruscijolia) is found only in the 
forest-clad areas and on the shady hillsides, while the smaller species of Coriaria are here 
completely absent. The thorny shrub wild-irishman, or " tumatakuri " [Discaria loumatou), 
is abrmdant on many of the hill-slopes, especially near Gabriel's Gully. Of all the 
shrubby plants, the two specie.^ of manuka {Leptospermum ericoides and L. scoparium) 
are the most plentiful ; near Lawrence and Wetherstones* in particular manuka forms 
an almost complete covering of the hillsides. The first settlers state that there was 
little of this plant in the early days, and that within late years in particular it has 
spread to a great extent. An explanation of this fact is fraught with considerable 
difficulties. Locally it is suggested that the numerous introduced birds have dis- 
tributed the seed, but this does not appear to be particularly likely, as the manuka 
affords no feed for birds, and in consequence is not a great resort for them. It is 
more probable that the constant burning of the grass has entirely destroyed the 

* The present Post Ofl&ce spelling of this name is " Weatherstone"; this, it is said, being the name of 
the discoverer of gold in the locality. The spelling adopted in the text is that of old geological and 
other reports. It is explained as a reference to the " cement " or sar.sen .stones (locally called " chinamen "), 
which are plentiful at Wetherstones, and as seen from a distance bear a resemblance to sheep. (See 
pp. 54, &c.). Hutton, Ulrich, and Cox, however, use the form Weatherstone or Weatherstone's. 



6 

mat-like covering of native plants, and that other vegetation has been kept down 
by rabbits, thus relieving the manuka from the competition that in former times 
prevented it from establishing itself in large quantity. 

On many of the hillsides, especially near Wetherstones, the native " flax " 
{Phormium tenax) grows in considerable quantity, and a mill is in operation at Evans 
Flat for the separation of the fibre. Over the greater part of the area the Phormium 
is absent. Another liliaceous plant of very general distribution throughout New 
Zealand is the cabbage-tree (Cordyline australis). It is frequent in the Tuapeka district, 
though not abundant anywhere. 

A plant that is excessively troublesome in the localities where the native vegetation 
has been least disturbed is the " lawyer " {Rubus australis). The only places where this 
is the case are the small areas of bush and of scrub land. The curious umbelliferous 
genus Aciphylla is found in many places, but it is not very abundant. The burnings 
of the grass lands and the acti\aties of the rabbits appear to have exterminated the 
plant over large areas, although when the gold-miners first reached the district it 
was abundant, especially on the river-flats. 

The principal plant - covering consists of native grasses. The most conspicuous 
of these are the txissocks. The so-called " red " tussock, or the oat-like tussock of botanists 
{Danthonia Raoulii), is the largest, and still covers much of the higher country. It 
is, however, much less abundant than formerly, and its growth is less robust owing 
to the constant burning to which it is subjected. The other abundant tussock is the 
hard fescue (Festuea duriuscula), which occurs almost everywhere, while the silver tussock 
{Poa australis) occurs rarely. Between the plants of these larger grasses small-growing 
species are still abundant, especially where the rabbit pest has decreased. Small kinds 
of Poa and Danthonia as well as Festuea growing under such conditions provide valuable 
pasture. It is important to state that in many places it seemed a few years ago as 
though these finer grasses had been entirely destroyed by the rabbits ; but it is found 
that now that these rodents have decreased in number the finer grasses have sprmig up 
again, and provide good and abundant pasture on land that was a little while ago 
almost unproductive. A grass that is fairly common sporadically throughout the district, 
but particularly in the wetter localities, is the sweet-scented grass {Hierochloe redolens). 
The conspicuous toetoe {Arundo conspicua) is common on the flats, but does not extend 
widely over the district. 

Compared with the usual New Zealand plant - covering, fern growths are less 
important here than elsewhere. The common bracken (Pteris aquilina) clothes some 
of the hillsides, especially in the southern and western parts of the district. Even 
there it does not grow particularly high or strong. Another common fern on the 
wetter and less sunny slopes is the Loniaria frocera, which in places covers consider- 
able areas. Tree-ferns are restricted to the small areas of forest. A Lycopodium 
(L. clavatum) is quite common on a great deal of the more hilly country, but it 
does not grow vigorously. 

British and European plants which have been introduced grow readily, and provide 
all the species that are used for plantations, hedges, fruit and agricultural industries. 
It is particularly noticeable that cereals, especially wheat, grow vigorously on all the 
flat spurs and hilltops as soon as the native vegetation has been removed. The ground 
has to be carefully cultivated, but if looked after it produces good crops as well as 
good pasture. 

Of the introduced plants the English broom has spread widely, and grows with 
special vigour in the stream-flats where gold-mining operations have changed the flats 
into shingle areas. Gorse also spreads readily, even on the hillsides and hilltops, and 
with the broom gives much trouble to the farmers. Introduced grasses, especially 
rye-grass and crested dogstail, grow well, and now constitute an important part of 
the pasture. 



Character of Land and Soil. 
From an agricultural standpoint the Tuapeka district can be divided into the 
following regions : — 

(1.) The flood-plains of the deeper valleys. 

(2.) The slopes and hilltops of the country formed of submetamorphic rocks. 

(3.) The country formed of schistose rocks. 

(4.) Patches of quartz-grits and " cements." 

(1.) Flood-plains of Deeper Valleys. 

The deeper valleys in the Tuapeka district are comparatively few, and their flood- 
plains are not wide. The flood-plain bordering the Molyneux River has a maximum 
width of half a mile. South of the Tuapeka mouth, and between that point and 
Beaumont, the plain disappears, the river there flowing in a youthful gorge. The 
flood-plains of the Waipori, Tuapeka, and Waitahuna are practically absent in the 
lower parts of these streams, but they expand considerably in their upper portions 
at Lawrence, Waipori Township, and Havelock (Waitahuna) respectively. These flats, 
however, in the three cases having proved auriferous, the soil and underlying gravels 
have been turned over and over in the search for gold. Thus their agricultural value 
has been much reduced, though a fresh deposit of silt from the hydraulicking-works 
farther up the stream has again partly restored their value. 

« 

(2.) Slopes and Hilltops of Country formed of Submetamorphic Rocks. 

At the present time the hill slopes and crests in the submetamorphic country 
constitute the most important agricultural areas. The hills rise to an elevation of 
1,500 ft. in places, though there is a gradual rise in the crest-line when followed 
north-eastwards from the eastern side of the Molyneux River. The hillsides are abi'upt 
only where they border the larger streams, and in many instances even these slopes can 
be ploughed. The spurs are all well rounded, and the hill-crests are nearly flat. The 
soil derived from the decomposition of the submetamorphic rock is a deep and fairly 
heavy clayey soil ; it supports a good pasture, and heavy crops of wheat and oats 
are obtained from it. 

(3.) Country formed of Schistose Rocks. 

The soil formed from the mica-schists which constitute the rock of the country 
north-eastward from Beaumont, Lawrence, Havelock, and Milburn is extremely light. 
The quartz, which occurs plentifully in the lenticles of the rock, is the most abundant 
constitutent of the soil. This country is moderately elevated, rising almost to 2,000 ft. 
over a great part of the area, and in places to a greater elevation. But little of this 
land has yet been cultivated, for in general it gives relatively poor results and requires 
much attention to keep it clean. On the other hand, it provides good pasture of native 
grasses on which large flocks of sheep can be maintained. Within the limits of the 
Tuapeka district the schist country is all at a relatively high altitude, and the climate 
is generally not suitable for cropping. It is therefore probable that the schist soils 
will never be of importance. 

(4.) Patches of Quartz-grits and " Cements." 

Within the Tuapeka district patches of quartz-grits, though common, are quite 
small. Their largest development is in the extreme east, on the western border of 
the Tokomairiro Plain, where they cover the submetamorphic rocks to a depth of 
100 ft. or less. Generally the soil fomid on this material is poor and meagre ; it is 



8 



always light, and produces poor crops. These remarks also apply in great measure 
to the soil developed on the coarser fragmental formations or " cements." In these, 
however, there is sufficient material in addition to the quartz to form a moderate 
soil, which generally will produce better crops than the soil formed on the quaitz-grits. 

Climate. 

The New Zealand meteorological department has no observing-stations within 
the Tuapeka district. Stations situated in adjoining districts are very differently 
situated with regard to physiographic features, and therefore have in all proba.bility 
a climate that is notably different from localities within the Tuapeka district. It is 
thus not possible to give any exact information about the climate. In general it may 
be said that the climate is intermediate between the damp and cloudy coastal climate 
of Dunedin and Kaitangata and the dry and sunny but frosty climate of Central 
Otago. There is hardly sufficient smishine and warmth in summer to allow apricots and 
peaches to ripen, as in Central Otago ; on the other hand, most kinds of fruit grow 
better than in Dunedin. 

The Dominion Meteorologist, Mr. D. C. Bates, has kindly supplied the following 
table showing the monthly and annual rainfalls at Balclutha, in eastern Otago, and 
at three stations in Central Otago : — 





Balclutha. 


Roxburgh. 


Gladbrook, 
Middlemarch. 


Clyde. 




In. 


In. 


In. 


In. 


January 


2-38 


202 


3-03 


1-57 


February 






210 


1-92 


1-99 


1-04 


March 






2-19 


1-88 


2-37 


1-39 


April 






1-83 


1-60 


1-66 


1-32 


May 






1-85 


1-66 


1-42 


0-99 


June 






1-61 


1-53 


1-62 


100 


July 






1-83 


1-43 


1-71 


0-76 


August 






1-55 


1-20 


1-19 


0-72 


September 






1-67 


1-38 


1-56 


0-89 


October 






2-41 


2-24 


2-72 


1-60 


November 






2-35 


2-21 


2-72 


1-33 


December 






2-46 


2-47 


3-22 


1-91 


Annual 


• 


• 


24-23 


21-54 


25-21 


14-52 



Literature. 

The earliest references to the geology of the Tuapeka goldfields are to be foimd 
in the Otago Provincial Gazette. The most important of these are, — 
Otago Provincial Government Gazette — 

1861, p. 203 : Gabriel Read's letter to the Superintendent of the Province 
announcing the discovery of gold. 

1861, p. 228 : J. T. Thomson's first official report on the Tuapeka goldfields. 

1862, p. 269 et seq. : Pyke, Vincent, " Report on the Early History of Gold- 

mining in Otago." 
1864, p. 135 : Pyke, Vincent, Goldfields Department Progress Report. 
Subsequently there are references in the Wardens' reports contained in the Reports 
on the Goldfields of New Zealand. The accessible reports prior to 1883 are : Pyke, V. 
— H.-7 1873, pp. 28-30. Carew, E. H. — H.-9, 1874, pp. 23-25 ; H.-3, 1875, 



Plate II. 




A. MoLYNEux Valley xear Tuapeka Mouth. 




B. Wetherstoxes Flat viewed from the South. 



Geol. Bull. No. 19 1 



[To face jjoge 8. 



9 

pp. 17-18; H.-3, 1876, pp. 5-6; H.-l, 1877, pp. 2-3; H.-^, 1878, pp. 23-24; 
H.-ll, 1879, pp. 27-28; H.-26, 1880, pp. 29-30; H.-17, 1881, pp. 32-34. Wood, 
J. Nugent— H.-19, 1882, pp. 33-35. 

References will be found annually in the Government volume of " Papers and 
Reports relating to Minerals and Mining " (Mines Report). With rare exceptions 
these refer purely to the output of gold and the condition of the mining industry. 
The exceptions are almost confined to Mr. Howard Jackson's descriptions of the 
Bluespur deposit from 1890 to 1912. 

1862. Lindsay, W. L. : " On the Geology of the Goldfields of Otago, New Zealand." 

Rep. Brit. Ass. Adv. Sci., pp. 77-80. 
1864. Unger, F. : " Fossile Pflanzenreste aus Neuseeland." Reise der Novaia. Geol. Teil, 

Band 1. 
1875. Hutton, F. W., and Ulrich, G. H. F. : " Geology of Otago." (Mills, Dick, 

and Co., Dunedin.) This work contains special detailed descriptions of many 

of the auriferous and mineral deposits of the Tuapeka district. See especially 

p. 93, Bluespur; pp. 195, 196, Gabriel's Gully Reef; pp. 197-199, O.P.Q. 

Reef ; pp. 180-181, Newer Drift ; p. 184, Waipori Copper Lode ; p. 185, 

Waipori Antimony Lode ; p. 186, Waipori Cinnabar ; p. 189, Brown Coal, 

Lawrence. 
1877. Cox, S. H. : " Report on Antimony-mine, Queen Charlotte Sound." Rep. 

G.S. during 1874-76, No. 9, pp. 2-6. 
1879. Cox, S. H. : " The Tuapeka Cements." Rep. G.S. during 1878-79, No. 12, 

pp. 42-53. 
1881. Rowe, W. E. : "On the Antimony-mine at Hindon." Rep. G.S. during 1879-80, 

No. 13, pp. 153-55. 
1881. Rowe, W. E. : " On the Stony Creek Antimony-mine, Waipori, Tuapeka Comity, 

Otago." Rep. G.S. during 1879-80, No. 13, pp. 155-56. 
1881. Rowe, W. E. : "On the Waitahuna Copper Lode near Waipori." Rep. G.S. 

during 1879-80, No. 13, pp. 156-58. 
1886. McKay, A. : " On the Antimony Lodes of Endeavour Inlet." Rep. G.S. during 

1885, No. 17, pp. 10-13. 
1892. Hector, J. : " Bluespur, Tuapeka " : Part of progress report in Rep. G.S. 

during 1890-91, No. 21, pp. xxii-xxvi. Also Henley breccias, pp. Iv-lviii. 
1892. McKay, A. : " On the Prospects of Coal near Otakaia, Otago." Rep. G.S. 

during 1890-91, No. 21, pp. 43^5. 

1892. McKay, A. : " On an Outcrop of Antimony-ore on Barewood Run, Taieri River, 

Otago." Rep. G.S. during 1890-91, No. 21, pp. 54-55. 

1893. Rickard, T. A. : " The Goldfields of Otago." Trans. Am. Inst. Min. Eng., vol. xxi, 

pp. 411^2. Partly reprinted in Mines Report, N.Z., 1893 (C.-3), pp. 109-11. 

1893. Rickard, T. A. : " Alluvial Mining in Otago." Trans. Am. Inst. Min. Eng., 

vol. xxi, pp. 442-73. 

1894. De Launay, L. : " Les Richesses minerales de la Nouvelle-Zelande." Paris, 

1894, pp. 22, 23. Extrait des annales des mines, Mai, 1894. 
1894. Hector, J. : " Bluespur " : Part of progress report in Rep. G.S. during 1892-93, 

No. 22, pp. xxxv-xxxix. 
1894. McKay, A. : " Older Auriferous Drifts of Central Otago." Mines Rep., C.-4. 

Reprinted in 1897. Perhaps the best accoiuit of the Bluespur and other 

" cement " areas occurs in this work. 
1903. McKay, A. : " Gold-deposits of New Zealand." Reprinted from the New 

Zealand Mines Record. 



10 

1906. Loughiian, R. A. : " The First Grold Discoveries in New Zealand." Reprinted 

fiom the New Zealand Mines Record. 
1908. Finlay.son, A. M. : " The Scheelite of Otago." Trans. N.Z. Inst., vol. xl, 

pp. 110-22. 

1914. Morgan, P. G. : " The Lawrence-Waipori District." 8th Ann. Rep. N.Z. Geol. 

Surv., part of pari, paper C.-2, pp. 154—156. 
1916. Mar.shall, P.: "Relations between Cretaceous and Tertiary Rocks." Trans. N.Z. 
In.st., vol. xlviii, 1916, p. 100. 

The following are of special importance in regard to the schists and their origin : — 

1875. Hutton and Ulrich : " Geology of Otago," pp. 29-32. 

1885. Hutton, F. W. : " Sketch of the Geology of New Zealand." Quar. Jour. Geol. 

Soc, vol. xli, pp. 199 et seq. 

1886. Hector, J. : " Outline of New Zealand Geology," pp. 84, 85. (Government 

Printer.) 
1900. Hutton, F. W. : " The Geological History of New Zealand." Trans. N.Z. Inst., 
vol. xxxii, pp. 162-63. 

1904. Van Hise, C. R. : "A Treatise on Metamorphism." U.S. Geol. Surv. Mono- 

graph xlvii. 

1905. Marshall, P. : " Geography of New Zealand." (Whitoombe and Tombs.) 

1906. Park, J. ; " The Geology of the Area covered by the Alexandra Sheet, Central 

Otago Division." Bull. N.Z. Geol. Surv. (New Series), No. 2. 
1908. Finlayson, A. M. : " Some Observations on the Schists of Central Otago." 
Trans. N.Z. Inst., vol. xl, pp. 72-79. 

1908. Park, J. : " The Geology of the Cromwell Subdivision, Central Otago Division." 

Bull. N.Z. Geol. Surv. (New Series), No. 5. 

1909. Park, J. : " The Geology of the Queenstown Subdivision, Central Otago." Bull. 

N.Z. Geol. Surv. (New Series), No. 7. 

1910. Park, J. : " Geology of New Zealand," pp. 34, 35. (Whitcombe and Tombs.) 

1911. Marshall, P. : "Geology of New Zealand," pp. 164, 181. (Government Printer.) 

1912. Marshall, P. : " New Zealand and Adjacent Islands." Handbuch der regionalen 

Geologie, Winter, Heidelberg, 5 Heft, Band vii, Abt. 1, pp. 17-21. 

1913. Lindgren, W. : " Mineral Deposits." (New York.) 

1915. Leith, C. K., and Mead, W. J. : " Metamorphic Geology." (New York.) 



11 



CHAPTER II. 





CULTURE. 




Page 




Inhabitants . . 


.. 11 


Gold-mining — continued 


Me<ans of Communication 


.. 11 


Quartz-mining 


Farming Industry 


.. 12 


Antimony 


Gold- mining . . 


.. 12 


Copper 


History of CJold Discovery 


.. 12 


Scheelite and Wolfram 


" Cement " Areas 


.. 13 


Mercury 


Alluvial Diggings 


.. 14 





Page 

16 
15 

16 
16 
16 



Inhabitants. 
All the country described in this report is settled, and, except in the northern 
portions, supports a fairly numerous population. The greater part of the settlers are 
engaged in farnung, and the soil is sufficiently rich over the soiithern and western 
portions to allow of a good living being obtained on relatively small farms. There 
are only two town.ships which have a population of more than one hundred ; these 
are Lawrence and Havelock, or Waitahuna. Waipori, at one time the home of at 
least two thousand minei-s, has now a population of eighty people only. These and 
other centres of population were originally mining camps, for they are situated quite 
close to the most important gold-pioducing localities, which for a long time yielded 
rich returns. In all cases the population is now only a fraction of what it was when 
gold-production was at its height. However, these townships, which were originally 
the temporary home of miners, have now become centres of the farming industry, 
and their permanence has thus been established. 



Means of Communication. 

A railway-line passes through the Tuapeka district from south-east to north-west, 
connecting up the larger townships. This railway for some distance runs generally 
parallel to the line that separates the' schist soil from the richer lands of the sub- 
metamorphic rocks, though it is about two miles south-west of that indefinite 
bomidary. 

The district is well roaded ; but in general the roads rise steeply from the railway- 
line to the summit-level of the surrounding country (about 1,000 ft.), and thence 
they continue on the tops of the spurs. These are the lines of least resistance ; and 
in the early days of gold-digging and of settlement the old bullock-drays were able 
to traverse the country by utilizing the spur-tops, without any preliminary work of 
road-construction. More recently less circuitous roads have been made, such as the 
road from Lawrence to Waipori and from Lawrence to Tuapeka West, but these roads, 
beuig forced to cross deep and steep valleys, present hills and grades which are not 
encountered on the old roads. The surface of the roads connecting the larger centres 
is covered with rubble, which is often only the broken schist or other rock obtained 
in the neighbourhood. This local material, however, usually makes a road that is 
not suitable for any but the lightest traffic, and therefore phonolite railed from Dmiedin 
is used to a considerable extent for roadmaking purposes. The lateral and branch 
roads either have a surface of local rock or have no macadam whatever, in which case 
they are, of course, in a bad state iti winter. The stream-valleys in general are 
not used for roads, as they are steep, rock-walled, and tortuous. The main exception 
is the Tuapeka valley, which is followed by a road for ten or twelve miles. 



12 

In the northern part of the district the roads are little used, and the surface 
is not macadamized. Generally the open nature of the country and the sloping grassy 
spurs make it possible to traverse all parts of the district with ease, and in the 
western and southern districts the numerous roads provide ready means of access. 

Farming Industry. 

At the present time the most important industries are those associated with 
farming. The relatively low altitude of the country, the low roimded spurs, and 
usually gentle acclivities make the greater part of the south-west of the area suitable 
for agriculture. Though the land is not particularly rich, careful cultivation and some 
manuring have made it capable of producing good crops of cereals as well as root 
crops. The area of cultivation is gradually extending, and the farming population 
is able to do well even when working holdings of quite a moderate size. 

The pastoral industry is generally of greater importance than the agricultural, 
for much of the land in the north-east and of the Waitahuna Heights is at too high 
a level for successful agriculture. Much of the more northerly portion of the area 
is formed of schist rock, and the soil derived from it contains so much quartz sand 
and pebbles as to make it extremely light. Under such conditions as these the 
land is devoted to pasture. The grasses are predominantly native species, and it 
is found that relatively a small number of sheep can be maintained on any given 
area. It follows that the pastoral runs must be of considerable size. The dis- 
appearance of the rabbits is having a great effect on the productiveness of the region, 
and it will soon be possible to subdivide some of the larger pastoral areas. 

Gold-mining. 

The Tuapeka district is well known in New Zealand as the place where the 
first important remunerative goldfield was discovered. The production at one time 
was enormous, and for a number of years the amount of gold annually obtained 
was considerable. Of late years comparatively little gold has been produced, but for 
some time the }deld has had an upward rather than a downward tendency. 

History of Gold Discovery. 

The early history of this goldfield is well stated by Vincent Pyke.* He says 
that the occurrence of gold in the Upper C'lutha was known to the Maoris. . Li 
1852 an exploring party of colonists obtained colours of gold in the Clutha gravels 
as far up-stream as Beaumont. From 1853 onwards various settlers foimd small 
quantities. 

Garvie is said by Pyke to have stated in 1858 that gold was found in the Clutha 
River above the jiuiction of the Manuherikia and in the Tuapeka Stream in sufficient 
quantities to make it probable that it would pay to work if set about in a. proper 
manner with some wholesale system of washing, such as sluicing. 

Black Peter (Edward Peters, a native of Bombay) was in 1857 finding gold in the 
Woolshed Diggings in the south branch of the Tokomairiro River. The same digger 
also obtained gold in Davy and Bowler's run near the north bank of the Tuapeka 
River. 

Mr. J. Robertson, for several years Mayor of Lawrence, informs the author that 
Gabriel Read found Peters's workings on the Tuapeka River, and from there prospected 
farther up the Tuapeka and Munro's Gully, where Mimro then had a small hut. 

* Pyke, Vincent: Otago Provincial Government Gazette, 1862, pj). 219 et seq. 



13 

From Munro's Gully Read passed over a ridge — the famous Bluespur — iiito Gabriel's 
Gully ; and about a mile down this gully, and nearly the same distance from Lawrence, 
he fomid really payable gold. He related the discovery of this important goldfield 
in the following words, written on the 4th Jime, 1861, to .Major Richardson, the 
Superintendent of the Province : — 

" I take the liberty of troubling you with a short report on the result of a gold- 
prospecting tour I commenced about a fortnight since, and which occupied me about 
ten days. During that period I travelled inland about thirty-five miles, and examined 
the ravines and tributaries of the Waitahuna and Tuapeka rivers. My equipment 
consisted of a tent, blanket, spade, tin dish, butcher's knife, and about a week's supply 
of provisions. I examined a large area of country, and washed pans of earth in 
different localities. I found at many places prospects which would hold out a certainty 
that men with proper tools would be munificently remunerated ; and in one place for 
ten hours' work with pan and butcher's knife I was enabled to collect about 7 oz. of 
gold." 

On the 6th July, 1861, Mr. J. T. Thomson, Provincial Surveyor, visited Gabriel's 
Gully. At that time there were already forty parties on the field ; and, of these, Read, 
Brookes, and Hardy had obtained 112 oz., J. Jenkins and four others 49 oz., while 
for a forenoon's work J. Cargill washed out 10 oz., and P. Lindsay 7^ oz. for four 
hours' work. 

In September, 1861, three thousand people were on the field, and the floor of the 
gully had been " gutted and ransacked in an extraordinary manner." The first gold 
escort which reached Dunedin, in August, 1861, brought down 5,056 oz. of gold from 
the Tuapeka. In his report Thomson gave a description of Gabriel's Gully and of the 
nature of the field which is worth quoting : — 

" The site of the field is a narrow valley 100 ft. to 300 ft. in width. This space 
is flat, and from thence on either side steep slopes rise 500 ft. to 800 ft. These 
slopes show argillaceous schistose rocks as the formation, in which nodules and veins 
of quartz exist abundantly. This formation is a very general one in the Province of 
Otago. The valleys run north and south, and the strike of the rocks is across this, 
or east and west. . . . The present' valley, both geologically and physically, is 
represented by many others out of the Lammerlaw and adjacent ranges of mountains, 
so it may be inferred that other fields will be fomid.'"* 

The large influx of miners caused by the discovery of gold in Gabriel's Gully 
provided abmidant practical experts for prospecting the surrounding country, and very 
soon the adjacent localities of Munro's Gully and Wetherstones were found to be 
payable. As early as the month of July, 1861, Gabriel Read and Captain Baldwin 
discovered the important Waitahuna field, some eight miles distant. 

" Cement " Areas. 

Work in these four localities soon showed that the valleys in every case were rich 
for a certain distance only ; they then suddenly became poor or were destitute of 
gold. It was at once realized that the gold was derived from a rock formation, 
which was passed where the sudden change in the value of the valley gravels took 
place. The hill forming the west side of Gabriel's Gully was then examined, and 
was found to be formed of an auriferous conglomerate. This conglomerate, which will 
be shown subsequently to be of Early Tertiary age, received the local name of 
" cement," and this has been retained to the present day. When exposed by mining 
operations the " cement " was foimd to have a bluish colour in its lower layers ; 



* Thomson, J. T. : Otago Provincial Oovernment Gazette, 1861, p. 228. 



14 

hence arose tlic name of Bluespur for that part of the hill which is formed of the 
conglomerate. Tliis famous Bluespur is a low ridge which separates the valley of Gabriel's 
(iluUy from that of Munro's Gully. Further work soon showed that the Bluespur con- 
glomerate was licher in the lower strata than the upper, and before long companies 
were formed with the object of working the rich bottom layers. The whole of the lower 
portion of the " cement " was thus removed, and was afterwards crushed, the gold con- 
tained in it l)eing saved, though not completely, by gravity separation methods. 

The other conglomerate areas at Wetherstones and Waitahuna were developed and 
treated in the same manner. Li addition, much of the upper portion of the con- 
glomerate has been sluiced away, and this sluicing is still in operation. The water- 
supply for this process is derived mainly from the Waipori River and its branches. 

In the meantime the river-gravels in the valleys of the Tuapeka and Waitahuna 
which contained the gold derived from the natural weathering of the " cement " have 
been continuously worked, and are still }aelding gold. In the early days of discovery 
individual miners, with claims 24 ft. square, were able to obtain highly payable results, 
and when the ground had been worked over by them it was successfully reworked by 
Chinese. Later on dredgmg was able to obtain still further gold from the same 
deposit, and lastly the ground has been treated more rapidly and in larger amount by 
hydraulic methods, with the result that even the small amount of gold remaining has 
yielded payable returns. 

Other deposits of auriferous conglomerate or '• cement " were afterwards discovered 
at Adams Flat on Woolshed Creek, a branch of the Tokomairiro River. This has 
been worked in a manner similar to that employed at the Bluespur. The small 
quantity of water available has, however, prevented the sluicing and hydraulicking which 
have been so productive at the Bluespur. If a larger water-supply can be obtained 
it is probable that this field will yet yield large quantities of gold. At present dredging 
is in progress, but this leaves imtouched a great thickness of conglomerate that could be 
treated by hydraulic sluicing. 

Alluvial Diggings. 

In nearly every stream alluvial-gold mining has been undertaken, and the work 
done by early miners can still be traced far up in the hills and momitains. Li some 
cases these isolated parties did exceedingly well, and all of them seem to have obtained 
some gold. There were thousands of miners on the field at one time ; and when there 
was lack of occupation, or when the production became lessened, these men went 
off individually or in parties and prospected every possible locality. It does not seem 
likely that any stream throughout any important length of its course has escaped 
the attack of the pick and shovel of experienced prospectors. Far up in the Lammer- 
law Mountains among the snows of winter the hardy miners worked, and any locality 
that showed promise of remunerative return was the scene of much expenditure of 
energy. Though without doubt some patches still remain, it is probable that they 
are either hidden beneath unfavourable-looking material or are in such remote spots 
as to render the expense of exploitation prohibitive. 

At Waipori the large river-flat is composed of loose quartz gravels that have been 
proved to be auriferous throughout. Dredging and hydraulic sluicing are the methods 
that have been employed for the treatment of these gravels, and a large amount 
of gold has been obtained from them. Only the upper layers of the deposit have 
been treated up to the present, and the depth itself is imknown except over a small 
area. Over the greater portion of the deposit the dredges worked on a false bottom — 
that is, they failed to reach the rock bottom on which the gravels were deposited. 
Dredging is entirely suspended in this district at the present time, and only one 



15 

hydraulic claim is working on the main flat. Here, as elsewhere in the Tuapeka 
area, there is a wholly inadequate supply of water for the treatment of the deposit. 
Nearly all the water that is available is already employed, every stream in the adjacent 
portion of the Lammerlaw Mountains supplying a quota. Not only does it appear 
impossible to bring in much more water, but it is commonly said that the streams 
which* are used at present are constantly decreasing in volume. The small fall of 
snow in the last few winters in particular has so decreased the areas of pond and 
of water-logged peat that the streams fail to obtain the supply which formerly, owing 
to the slow drainage, used to last throughout the summer, even without any large 
amount of summer rainfall. 

Quartz-mining. 

\i\ the early days of mining enterprise — and, indeed, up to the present day — there 
has been a feeling abroad that the rich alluvial deposits of the Tuapeka district must 
have been derived from some definite system of auriferous lodes. Search for these 
was soon organized and made. As a result a number of quartz bodies were opened 
out, but none of these up to the present time has been an important gold-producer. 

There is throughout the distiict a large amount of quartz interlaminated with 
the other materials of the schist rock, and much difference of opinion has been expressed 
as to whether this quartz is auriferous, and thus the source of the metal in the rich 
detrital deposits. The view that this is the source of the gold was expressed by 
Hutton and Ulrich in 1875.* This view was supported by Rickardf in 1893, and 
his statements on the subject have been largely quoted by McKay and others. Pro- 
fessor D. B. Waters, of Otago University, who has probably had unrivalled experience 
in the assaying of Otago auriferous rocks, assures the author that the assays of quartz 
laminations always give some amount of gold. McKay J advocated this view in 1903, 
as did Marshall§ in 1904. On the other hand, Finlaysonjl in 1907 opposed this idea, 
and Park^ had previously expressed similar views in 1906, which he repeated in 1910. 

The idea that the gold is derived from the quartz laminations of the schist has 
been held for two reasons : (1.) Actual occurrences are quoted in which the schist 
carries gold. These, however, have been challenged on the grounds that (a) some 
of these occurrences are in reality branches of true lodes ; (6) the auriferous schist 
is really part of a so-called " lode formation " — that is, a crushed zone of schist which 
has been penetrated by metal-bearing solutions that have deposited gold as they 
traversed the rock. (2.) The other argument that has been advanced is of a general 
nature. The large extent and richness of auriferous gravels throughout Otago is pointed 
out in conjunction with the fact that auriferous lodes are few, poor, and small. 

The author is inclined to think that the gold has not been derived, even in the 
main part, from distinct quartz lodes, but from auriferous zones of the schist, especially 
where this has been crushed. The question will, however, be mentioned again later 
(see Chapter V, p. 42). 

Antimony. 

The existence of a body of antimony -ore on the .south slope of the Lammerlaw 
Mountains in Stony Creek valley has long been known. Some years prior to 1880, 
according to Mr. E. H. Carew, Goldfields Warden, a trial shipment of the antimony- 

* Button, F. W., and Ulrich, G. H. F. : " Geology of Otago," 1875, p. 157. 

t Rickard, T. A. : Trans. Amer. Inst. Min. Eng.,"vol. .\.\i, 189.'}, pp. 442-73. 

t McKay, A. : " Gold Deposits of New Zealand," 1903 p. 67. 

§ Marshall, P. : " Dunedin and its Neighbourhood," 1904, p. 93. 

II Finlayson, A. M. : Trans. N.Z. Inst., vol. xl, 1908, pp. 77-78. 

if Park, J. : N.Z. Gaol. Surv. Bull. No. 2, 1906, p. 33 ; " Geology of New Zealand," 1910, p. 370. 



16 

ore was sent to (rreat Britain. About 1879-80 a considerable quantity was mined and 
exported. The difficulty of access and expense of transport soon caused the venture to 
be abandoned. Of late years no mining of this metal has taken place. 

Copper. 

In the gorge of the upper part of the Waitahuna valley a deposit of copper-ore 
in the form of chalcopyrite has been known since 1865. A small quantity was at 
one time mined, but for a long time no work has been done on the lode. 

SCHEELITE AND WoLFRAM. 

Scheelite occurs over a wide portion of the Waipori end of the district, including 
the Lammerlaw Mountains. Li many of the sluicing claims scheelite occurs with the 
gold in the concentrates in the sluice-boxes. A few quartz lodes carrying scheelite have 
also been found, but all that have been investigated up to the present time have 
been discontinuous, and have not yielded any great quantity of muieral. Recently 
(1917) the discovery of small quantities of impure wolfram in the Waipori district has 
been announced (see p. 40). 

Mercury. 

At the top part of the Waitahima Heights fine specimens of cinnabar have been 
obtained, but prospecting operations have not yet shown the existence of a large 
ore-bodv. 



Plate III. 













4i 








^v. 



J^'^'^ 




■j.v 






'« 






««S^ 



# 






..^ 



A. Samples of Gold from Tuapeka Dlstrict. 




B. Nuggets of Gold from R. J. Cotton's Claim, Lammerlaw Creek, Waipori. 



Geol. Ball Xo. 19.] 



[To face page 16. 



17 



CHAPTER III. 



SEQUENCE OF FORMATIONS AND GEOLOGICAL HISTORY. 



Sequence of Rock Formations 
Volcanic Rocks 



Page 
17 
19 



Periods and Directions of Folding 
Table of Geological Event.s 



Page 
19 
20 



Sequence of Rock Formations. 

No detailed geological work has previously been done in the Tuapeka district, 
though the auriferous-cement areas near Lawrence and Waitahuna have been the 
subject of close scrutiny by Hutton, Cox, and McKay. The rock formations that 
appear in it are, however, similar to those that have a wide occurrence in Otago, and 
these have been the subject of considerable geological discussion. On the extreme south- 
west the rocks, in hand-specimens at least, are but slightly altered greywackes and 
mudstones. These are succeeded in a north-easterly direction by other rock-types in 
which a definite development of separation-planes and laminated structure becomes 
apparent. Still farther to the north-east definite mica-schist with large and prominent 
quartz lenticles makes its appearance. Hutton made these three rock-types the 
representatives of three different geological systems, called respectively — Kaikoura, 
of Carboniferous age ; Kakanui, of Upper Silurian age ; Wanaka, of Lower Silurian 
age. No fossils, however, were found by him in any of these rocks, and he remarks 
of the Kakanui, " The formation is quite conformable to and passes insensibly into 
the Wanaka formation. The distinction between them is quite arbitrary. . . . 
The difference between them is simply owing to the older and lower formation having 
undergone more metaraorphism than the upper."* 

Between the Kakanui and Kaikoura formations, Hutton says, the mapping demon- 
strates an unconformable relation, and he cites a definite instance of this in a section 
some distance to the west of the Tuapeka district. A fourth formation of still less 
altered rocks — the Maitai System of Triassic age — ^is described by Hutton as resting 
on the Kaikoura System. He says the junction between these two is not very clear, 
and in the Clutha there appears to be a uniformity between the two, but it is not 
well marked. t His Maitai System, however, does not occur in the Tuapeka district. 

In the map attached to McKay's " Report on the Older Auriferous Drifts of 
Central Otago, 1897," the extreme south-western part of the district is classed as 
Devonian, while the remainder is classed as Upper and Middle Schists, but no definite 
geological age is mentioned for these. 

MarshallJ has classed all of these rock-types in his Maitai System of Trias-Jura 
age. The schists he regards as metamorphic equivalents of the greywackes and shales 
lying to the south-west of the Tuapeka district. 

It thus appears that all geologists are agreed that the rocks in the south-west 
are relatively imaltered shales and greywackes, but there is a progressive metamorphism 
towards the north-east. Opinion merely differs as to whether these altered rocks are 
to be classed in the same systems as those that are unaltered, or whether there are 
two or three geological systems. If the latter is the case, opinion differs further as 
to the locality of the divisions between the different systems. 

* Hutton, F. W. : " Geology of Otago," 187.5, p. 33. 

f Hutton, loc. cit., p. 38. The word " uniformity " may be a misprint for " unconformity." 
J Marshall. P.: "Geology of New Zealand," 1912, p. 178; " Handbuch der regionalen Geologic," 
Band vii, Abt. 1, pp. 18, 21, Heidelberg, 1912. 

2 — Tuapeka. 



18 

Here, as elsewhere in New Zealand, difference of opinion has been due to the entire 
absence of fossils in the rock-masses hitherto mentioned, and also to the absence of well 
marked and recognizable lithological horizons. Until some definite information of the 
nature suggested is available, division of these rock-series must remain a matter of opinion. 

The general structure revealed in these older series of rocks is a decided dip to 
the south-west or south-east, though there are here and there relatively small areas 
where other dips prevail. In the extreme north-east of the district, on the Lammer- 
law Mountains, the dip turns over to the north-east ; but whether this change con- 
tinues for any distance is not known. At Barewood the schist lies nearly horizontally. 
As the age of these rocks is not yet known it is not possible to state when the 
metamorphic structure was impressed on them. It is, however, well known that some 
twelve miles south-west of the Tuapeka district, at the Kaihiku Gorge, fossils have 
been found in rocks similar to the unaltered grej'wacke of the district. These 
fossils were considered by McKay and Hector to be of Permian age. Recently, however, 
Mr. C. T. Trechmann has collected specimens, and he informed the writer that the 
fossils are distinctly of Middle Triassic age. These rocks have certainly taken part in 
the general folding of the whole district, consequently the folding must be post-Triassic. 
It has generally been assumed that the metamorphism was impressed on the rocks 
at the period of folding. Some facts noted by the writer seem to be opposed to this. 
Thus near Stony Creek and at Balclutha, a few miles south-west of the area, foliation- 
planes and shaly partings were found to be different. Hitherto it has been gene- 
rally assumed that in the Otago region the schistose structure had been developed in 
the stratification-planes, but the above fact shows that this is not the case in all 
localities. In general, however, it is probably true, for where the texture of the rock 
changes it appears to be the case that the parting-planes are parallel to the plane 
that separates the two textural varieties of the rock. This matter, however, requires 
further investigation, which cannot be made in the Tuapeka district, for within its 
boimdaries no stratification-planes can be distinguished in the rock, while the jointing, 
parting-planes, and segregation veins render the whole rock-structure most confusing and 
diflB.cult of interpretation. 

Whatever the age of these gre}Tvackes and schists, it is certainly the case that 
the main features of the folding, and probably all the true folding as well as the meta- 
morphic changes, had taken place before the deposition of the next series of rocks. 
This series is the so-called auriferous " cements " of Lawrence and Waitahmia, and, 
associated with them as an upper facies, the well-known quartz gravels which are 
often associated with coal. The " cement " is really a conglomerate, and it consists 
mainly of pebbles and boulders of schist. It is thus evident that not only had the 
metamorphism of the schists taken place, but an erosion interval had intervened of 
sufficient length to allow of the removal of the covering of overljTng rocks and the 
exposure of the schist itself before the deposition of the " cement." In addition, 
erosion of the schist thus micovered had proceeded so far as to provide a large 
quantity of detrital material. 

The age of this " cement " and quartz-gravel formation is probably Upper Cretaceous 
(Mfestrichtian) or Lower Eocene, and its disposition generally over the surface of the 
eroded grejrwackes and schists gives clear evidence of an extensive marine transgression. 
It is, however, probable that the " cement " merely fills stream-valleys that were 
formed during the period of erosion, and this filling probably preceded the actual 
advance of the sea-margin by a brief intei-val. The quartz gravels, however, are 
believed to be a true littoral marine formation. This statement is in accord with 
the views of McKay, but Button, Cox, Rickard, and Park have regarded the " cement " 
as a glacial formation, and Park even looks upon it as a deposit of Pleistocene glaciers.* 

* Park, J. : " Geology of New Zealand," 1910, p. 187. 



19 

Within the limits of the Tuapeka district no general stratified formation of younger 
age than the quartz gravels is to be found, though at Milburn, a few miles to the east, 
they are succeeded in regular stratigraphical sequence by greensands which are them- 
selves covered by a thick bed of foraniiniferal limestone. There is nothing to show 
whether these strata were ever deposited in the Tuapeka district itself, though the 
geological succession in many other neighbouring localities indicates that such was 
probably the case. 

The only other stratified deposits are river-gravels and surface clays, both of which 
may be regarded as mainly of Recent origin. The river-gravels have a local develop- 
ment which attains its maximum in the Waipori valley at an elevation of 1,100 ft. 
above sea-level. Other important areas are found in the middle valleys of the Tuapeka 
and Waitahuna. In the valley of the Molyneux the gravel-deposits are almost wholly 
restricted to the bed of the river itself. The surface clays cover the rocks very 
generally. For the greater part they have evidently been formed by the decomposition 
of the greywacke or schist. , 

Volcanic Rocks. 

No rocks of igneous origin have previously been described from this district. It was, 
however, found that a large lava-flow of coarse basanite covered the quartz gravels 
between the Tokomairiro Gorge and the plain of the same name. This lava appears to 
have been subaerial in its origin, as it is highly vesicular in portions, and much of its 
surface was strongly oxidized. If the greensand and limestone were ever deposited in 
the Tuapeka district the outflow of this basic lava must have been subsequent to their 
removal by denudation. 

Periods and Directions of Folding. 

The Tuapeka district is a portion of the main folded axis of the South Island of 
New Zealand. It has been frequently pointed out that this axis has a west-north-west 
to east-south-east direction in this part of New Zealand. Suess* described it as a chain 
independent of the main north-east - south-west chain, which it meets in a syntaxis. 
Gregoryl regarded this part of Otago as part of an old mountain-system older than the 
Southern Alps or other mountain-structure in New Zealand, except some mountain-lines 
in the extreme north of the North Island which have the same trend. Hutton,J who 
published his fullest account of New Zealand in 1885, both then and in 1899 spoke of this 
part of Otago as a portion of the great anticUnal of New Zealand, which took a south- 
easterly bend in Otago. Park§ has adopted Gregory's view in regard to the relative age 
of the mountainous areas of New Zealand, while Marshall|| tentatively has adopted the 
view put forward by Hutton that the Otago mountain-axis is merely a continuation of 
the great axis of the Southern Alps, which has been bent round to the south-east in 
this portion of the country. 

The relation of the folds of this Otago area to those of the Southern Alps needs in 
general no discussion here, as the problem has no special significance in connection with 
the area that is here described. The only point that has a special bearing on this 
district is the question as to whether the folds represent an older period of mountain- 
formation, as maintained by Gregory and Park. It has already been mentioned that 
towards the south-west the rocks gradually become less metamorphic, and that the schists 

* Suess, E. : "The Face of the Earth " (English translation), vol ii, 1906, p. 144 ; vol. iv, 1909, p. 299. 

t Gregory, J. W. : " Stanford's Compendium of Geography : Australasia," vol. i, 1907, p. 569. Also 
"Geography: Structural, Physical, and Comparative," 1908, p. 271. 

X Hutton, F. VV. : " Sketch of the Geology of New Zealand," Q.J.G.S., vol. xli, 1885, p. 195. Also 
Trans. N.Z. Inst., vol. xxxii, 1900, p. 167. 

§ Park, J. : " The Geology of New Zealand," 1910, p. 11. 

II Marshall, P. : " Handbuch der regionalen Geologic," Band vii, Abt. 1, p. 57, Heidelberg, 1912. 

2'— Tuapeka. 



20 

are finally replaced by greywackes and mudstones. Still farther — as much as ten miles — 
to the south-west fossiliferous rocks of the same types are met with. They are of 
Triassic age, and are bent into steep folds striking in a direction parallel to the Otago 
mountain-axis. This appears to dispose of the idea that the Otago axis is of greater 
antiquity than the Triassic, unless, indeed, the rocks of the Triassic period display 
posthumous folds merely. Jn view of the intensity of the folding, its remarkable 
regularity and continuity, it seems that this suggestion cannot be entertained. The 
view supported here is, therefore, that the Otago structural axis is merely a continuation 
of the axis of the Southern Alps bent round to the east-south-east, and that the folds 
are at most of Lower Jurassic age. 

As already remarked, a prolonged period of erosion succeeded the formation of this 
mountain-axis, but at an equivalent of the highest Cretaceous at earliest, or perhaps 
Lower Eocene, a great marine transgression took place consequent on a general epeiro- 
genic movement of depression. Elevation occurred again in the Late Tertiary, and was 
accompanied by a considerable amoimt of faulting. This elevation lasted sufficiently 
long to allow of the removal of nearly all the Tertiary formations, except where they 
were protected by faulting or were so resistant as to defy eroding action. At the 
close of this period of elevation the surface of the land was reduced to a peneplain. 

In still later geological times a general tilting-movement from south to north has 
occurred, and has caused all the larger streams to incise their channels deep into the 
peneplain. This movement has been associated with a certain amount of faulting of a 
local nature only, but with thrust of a much more important character. To these 
movements of tilting from the south to north and of thrust from south-east to north- 
west all the more important features of the present surface owe their origin. 

Table of Geological Events. 

Pre-Jurassic . . . . Deposition of a thick mass of littoral sands and muds. 

Jurassic . . . . . . Intense folding of these sediments, with complete meta- 

morphism of those near the centre of the disturbance. 
Cretaceous .. .. Continuous erosion. 

Highest Cretaceous or Lowest Movement of depression commenced, and the area probably 

Eocene one of marine deposition imtil the Late Tertiary. 

Highest Tertiary . . . . General elevation without folding, but some faulting. Forma- 

tion of peneplain. 
Pleistocene . . . . Tilting, with some faulting and much thrust-movement. 



21 



CHAPTER IV. 



PHYSIOGRAPHY. 



Mountains and Hills . . 
Uplands 

Waitahuna Heights 
Lammerlaw Mountains 
Details of Surface Features 

Rivers 

Molyneux River 



Page 
21 
21 
21 
22 
22 
24 
24 



Rivers — continued. 

Tuapeka River 

Waitahuna River 

Waipori River 

Basins in Stream-valleys 

Tokomairiro River . . 
Tokomairiro Plain 



Page 

25 
25 
25 
26 
26 
26 



Mountains and Hills. 

The surface features of the Tuapeka district are, in general, of a simple nature. If 
the highlands in the north-east of the area be ascended it is at once seen that there 
is a general uniform and gradual descent of the surface from the north-east to south- 
west — that is, to the valley of the Moljmeux River. The hill-summits in this north- 
east portion rise to about 2,000 ft. ; and this elevation is gradually reduced as the 
country is followed to the south-west, until near the river it is 150 ft. at most. This 
gradually sloping surface is, however, not quite continuous. For the most part it 
is drained by streams which ftow in gullies with floors only 100 ft. or so below 
the level of the general surface. The larger streams, however, traverse the country 
in steep gorges of considerable depth, and there are in addition 9. few relatively 
small basins. This general slope of the country, however, does not apply to its 
more easterly portion. When an observer looks to the south-cast and east from 
Lawrence an extremely .steep slope is noticeable, rising rapidly to an elevation of 
1,000 ft. above the nearer surface. The line of this steep scarp is directed nearly 
north-east and south-west, and it extends throughout the breadth of the district. 
This scarp is called the Waitahuna Heights. From its crest the ground falls with 
moderate slopes towards the south-east, and it soon reaches the level of the Toko- 
mairiro Plain which bounds the district in that direction. 

Uplands. 

The uplands, as previously stated, rise to an elevation of about 2,000 ft. in the 
north-east of the district. These uplands have a relatively level surface and even 
crest. As a natural result they were utilized for all the roads that connected the 
settlements, in preference to the rocky and tortuous river-gorges. The general surface 
of the uplands is more of the nature of gently undulating downs than of hilly country. 
The smaller streams that traverse them have shallow valleys with gradually sloping 
sides. Rock-outcrops on these uplands are unusual. Generally the whole surface is 
covered to a considerable depth with clay, formed from the decomposition of the rock. 
The larger streams, however, have gorge-like valleys, and precipitous rock-outcrops 
hem them in for the greater part of their length. 

Waitahuna Heights. 

The Waitahuna Heights constitute the highest elevation in the district. The 
abrupt scarp directed from north-east to south-west makes them conspicuous through- 
out. Their highest point in Waitahuna Hill rises to 2,248 ft. only, and thus their 
prominence in the landscape merely emphasizes the statements previously made about the 



22 

slight elevation and low relief of the uplands. The surface of the Waitahuna Heights 
in all respects resembles that of the uplands, though the streams have somewhat deeper 
valleys ; and the slope of the surface, here directed to the south-east, is considerably 
steeper than that of the uplands, which is directed to the south-west. It is a notice- 
able fact, and of tectonic importance, that there are on the north-west and south- 
east sides of this district, though just outside of it, two parallel lines of similar 
escarpment, with the same north-west aspect. These are the coastal hills lying to the 
south-east of the Tokomairiro Plain, and the Blue Mountains lying to the north-west 
of the lower middle part of the Molpieux valley. It is a reasonable inference 
that these lines of escarpment owe their formation to the same general earth-stress. 

Lammerlaw Mountains. 

The elevated ground, of an average altitude of 3,000 ft., that goes by this 
name has a relatively gentle slope on the south, but a steep decliv-ity on the 
east, where it rises somewhat abruptly from undulating coimtry which has an 
elevation of about 2,000 ft. The summit of the mountainous area is gently midulat- 
ing, for the streams which drain it have not cut deep valleys, and only the larger 
of them have steep gorges. The smaller streams have valleys that possess the 
aspect of maturity. These features strongly suggest that the mountainous region has 
only recently been elevated to its present station and that an extended cycle of 
erosion has just been inaugurated. 

Details of Surface Features. 

The actual surface of the mountains is, for the greater part, covered with a thick 
growth of peat vegetation, which in places has so blocked the drainage-channels that 
ponds of relatively large size have been formed, and elsewhere deep bogs extend 
over much of the surface. The constant firing of the dense native tussock-grass by 
the miners and settlers has rendered the surface far firmer than it was formerly. 
This has become especially pronomiced within recent years because of the small fall of 
winter snow, which has hardly sufficed to saturate the peat when the spring thaw has 
taken place. The live-stock which graze on the mountains during the summer have 
helped to consolidate the surface of the ground, and have decreased its water-holding 
capacity. 

As the Lammerlaw Moimtarns only touch the northerly fringe of the Tuapeka 
district, it was not possible to examine more than a small part of them. It is there- 
fore unwise to do more than suggest their origin. The prominent scarp of the south- 
east face is generally parallel to the still more prominent south-east scarp of Maimgatua, 
and this occurrence suggests the action of a thrusting force from the north-west. The 
surface features of the mountains and of Maungatua are such as to suggest that the 
high country has been raised to its present altitude quite recently, for the larger 
streams have valleys which present features of extreme youthfulness, while the smaller 
streams have not yet begun to respond to the initiation of the present cycle of erosion. 

The suggestion made here implies the operation of a thrusting force from the 
north-west, while the Waitahuna Heights, which lie some distance to the south, have 
been explained as due to the action of a thrusting force from the south-east — precisely 
the opposite direction. Between these two districts there flows the Waipori Kiver, 
which traverses a distinct gap separating the region that has its steep slopes and 
scarps to the east from that which has similar slopes facing the west. It is perhaps 
wise to state at this point that these steep slopes do not appear to be related in 
any way to the stratification, folds, or other rock-structures of the district. 



23 



t 



4 




Faults 

Probable Fault-planes .- \ 

Thrust Scarps \ 

D'irection of thrust X 



■NxiggetPt 



MAP OF 

TUAPEKA DISTRICT 

Showing Direction of 
Normal Fault -lines and Thrust- p lanes 



Scale of Miles — 

10 5 10 
L.JI I I I I L_i I I I l_ 



20 

I 



24 

The mature surface which has been described as characteristic of the Waitahuna 
Heights and of the Lammerlaw Moiuitains is not less marked in the rest of the 
upland country, which has the gradual slope from the north and east to the valley 
of the 'Clutha River. Here again the present elevation of the land must have been 
recently acquired, for only the larger streams have notably deformed the undulating 
surface of the old peneplain. A slight tilting-movement appears to have acted here. 

That such thrusts and tilts have actually occurred will probably not be granted 
by many geologists in the absence of more definite evidence. Actual instances of thrust- 
movement are, however, plainly seen in two localities. One of these is in the 
Wetherstones goldfield, where it has been clearly exposed by the sluicing operations of 
the Crescent Claim. Here the mica-schist of supposed Triassic age has been thrust 
over the conglomerate or " cement " of Early Tertiary age. The other instance is in 
the valley of the stream which enters the east side of the Tokomairiro Plain four 
miles north-east of Milton, where again Triassic rocks have been thrust over Early 
Tertiary conglomerates. In the former locality there does not appear to be any definite 
relation between the thrust-movement and the topography of the locality. In the 
latter case, however, the locality is on the line of scarp of the coastal range of hills, 
where it rises with considerable abruptness from the level of the Tokomairiro Plain. 
Another thrust-plane is distinct in a railway-cutting one mile east of the Big Hill. The 
impression produced on one who observes this district is that imtil the latest geological 
times the surface features — uplands, Waitahuna Heights, Lammerlaw Mountains, and 
Mangatua Mountain — all formed portions of an extensive peneplain, the surface of which 
has been dissected by streams, but still more changed by thrust-movements. 

A curious feature of the hilly country of the Tuapeka district is found in the spurs 
which are directed to the south-west. There is a very general and conspicuous difference 
between the acclivities of these on their north-west and on their south-east slopes. 
On the north-west slopes the spurs are gently romided, and are covered with some 
5 ft. or 10 ft. of clay which, as road-cuttings show, has been clearly derived from 
the underlying rock. This frequently supports luxuriant crops. The south-east slopes 
of the spurs are steep and rocky, and in nearly all cases have not been cultivated. 
This contrast is in no way related to rock-structure, for it is found in many cases 
opposed to the dip of the strata or the foliation. It is believed that this is due 
to climatic influences and frost-action. The roimded slopes are exposed to the smi 
and to warm dry winds ; they are thus subject to rapid changes in temperature 
and moisture ; these influences cause the rock to break down into clay quickly. 
The south-east slopes are not subjected to direct sun-heat, and the frost may 
remain on them all day ; they are also protected from the drying winds, and thus 
remain constantly moist. Such different conditions would probably cause the weathering 
of the rock on the north-west side to be rapid and on the south-east side slow. 

Rivers. 
No streams of any size have their whole courses within the limits of the Tuapeka 
district. The largest river of the South Island — the Molyneux — bomids it on the south 
and west. The Waipori River lies within its extreme northern portion, and flows from 
west to east. Elsewhere the Tuapeka and Waitahuna rivers flow across it from north- 
east to south-west, and aftenvards join the Molyneux, while the Tokomairiro has an 
independent existence, passing out of the south-east of the district and within twenty 
miles reaching the coast after traversing the coastal range of hills through a deep gorge. 

Molyneux River. 
This large stream, rendered turbid at all times by the mud contributed to it by 
gold-working, throughout its length flows with a rapid current. Its rocky banks 




D 

iz; 
H 



Q 
O 

w 

H 
(« 
O 

3 
o 
o 






o 
Q 

Ph 
P 

o 






25 

and the jagged points that from time to time project above its surface announce 
plainly that the stream has not reached its base-level of erosion. On its margin 
there is usually a narrow fiat some 10 ft. above its surface, from which many rocks 
project, but, except for this, its banks rise rapidly to a height of 150 ft. in the south- 
west and to 800 ft. or 1,000 ft. in the west portion of the district. Near the Tuapeka 
mouth the high rock cliffs that bound the river-valley can be clearly seen to be 
water-worn to a height of 300 ft. above the valley-floor. This fact demonstrates that 
the gorge of the river has been excavated in the most recent times — in other words, 
the force to which the tilting of the district is due has acted more recently than 
the other forces to which it owes the mam features of its physiography. 

Tuupeka River. 

Two tributaries of the Moljaieux- — the Tuapeka and the Waitahuna — drain by 
far the larger part of the Tuapeka district. The Tuapeka River rises in the north and 
highest part of the uplands at an elevation of about 2,500 ft., and flows a little west of 
south for a distance of thirty miles. Its headwaters lie in shallow valleys with gently 
sloping sides, but within a few miles the valley becomes deep with nearly vertical 
sides, and this form is maintained until two miles above Evans Flat, where it widens 
out into a basin nearly a mile wide. This basin is continued again in the Tuapeka 
Flat with another up-valley con thi nation in the Tuapeka Creek as far as Lawrence, 
and again in the Wetherstones Flat. Below the Tuapeka Flat the valley again becomes 
steep-sided and gorge-like until it issues into the valley of the Molyneux. Throughout 
the greater part of its course from the Tuapeka Flat to the Molyneux, and also 
within a large part of the Tuapeka Flat, the valley is boimded by a distinct terrace 
which rises to a height of about 30 ft. above the level of the stream. This terrace 
has proved highly auriferous throughout the greater part of its length. 

Waitahuna River. 

The lower part of the valley of the Waitahuna River is parallel to that of the 
Tuapeka, and is therefore directed to the south-west. Two miles above Havelock 
(Waitahuna) the stream forks ; the Bungtown branch here joins it on the west and 
right-hand side, while the main stream continues its north-east course. Ten miles above 
Havelock the stream turns rather rapidly to the north-west, and is here known as Reedy 
Creek. 

In the upper portions of its valley the Waitahmia has the same general character- 
istics as the Tuapeka — first the wide open valleys of the headwaters, then the restricted 
gorge of the next portion, followed by the expanded flat at Havelock, where there is an 
area of two miles by nearly one mile of level land. Below the Havelock Flat the 
stream enters a gorge, which is continued for some fifteen miles until the valley of the 
Molpieux is reached. Li this case, however, the lower gorge has no auriferous terraces 
on its sides. 

Waipori River. 

The Waipori River derives the greater part of its water from the slopes of the 
Lammerlaw Mountains. Its course is generally directed from west to east. Its 
headwaters flow in open valleys in the momitains, but they are more deeply incised 
before they reach the main stream than are the feeding streams of the Tuapeka and the 
Waitahuna. The main stream flows in a deep gorge for some twenty-five miles until 
five miles above the Waipori Township, when it opens out into a flat plain about 
half a mile wide, which continues almost without interruption for fifteen miles, where 
the stream is joined on the left side by the Post Office Creek (or Verter Burn). The 
miited waters then enter a profomid gorge between the Mamigatua Mountaui and the 



26 

Waitahuna Heights. Within a distance of three miles the floor of this gorge falls 
nearly 1,000 ft., and this provides the head of water from which electric energy is 
developed for the supply of light and power for Dunedin, twenty-six miles distant from 
the gorge. 

Basins in Stream-valleys. 

It is a peculiar fact that the three larger streams described all have an expansion 
in the middle portions of their courses, with a gorge portion above and below in each 
case. It is thought that these features can be explained only as a result of differential 
land-movements such as small local faults during the tilting or, in the case of the 
Waipori, by a thrust-movement which has been sufficiently rapid to dam up the 
stream temporarily. The small lake-basins thus formed soon drained over the lowest 
point of their containing-walls, and a gorge was quickly cut by the outflowing water. 
At the same time much gravel was brought by the small streams which entered the 
lake, and a gravel plain was formed, which in the case of the Waipori attained con- 
siderable dimensions. 

ToJcomairiro River. 

The Tokomairiro River leaves the Tuapeka district on the south-east in two 
branches, called the eastern and western branches. Both of these have a general 
north-west to south-east course, which is entirely confined to the eastern slopes of the 
Waitahmia Heights. Both of the branches flow in deep and precipitous gorges, that 
of the west branch being perhaps the most abrupt and deepest gorge in the district. 
The headwaters of these streams, again, are shallow valleys with gently sloping sides 
at the crest of the Waitahuna Heights. The west branch of the Tokomairiro takes 
a sudden bend at Mount Stuart, and thereafter flows to the south-east into the Toko- 
mairiro Plain. Below Momit Stuart it has a relatively wide valley, the floor of which 
has been dredged for gold. 

Tokomairiro Plain. 

The Tokomairiro Plain is an area of low land which bounds the whole district 
on the east. This plain has a floor of gravel covered by a rich soil. The origin of this 
low-lying area is probably to be fomid in the series of thrust-movements to which 
the elevation of the Waitahuna Heights and of the coastal range has been ascribed 
in a previous page. The plain is only a portion of a continuous low-lying area which 
extends from Mosgiel in the north to Kaitangata in the south — a total distance of 
fifty miles — and it is noticeable that the three larger streams that enter it from the 
western highlands cross it transversely, and afterwards pass through the coastal range 
in deep gorges. The plain is bounded on the west by the gently rising ground of 
the eastern slopes of the Waitahuna Heights. On the east the coastal range rises 
far more abruptly, and generally attains its highest summits on the very border of 
the plain. This suggests that the heights and coastal range are blocks thrust up 
from the east. On the banks of a small stream flowing west from the coastal range 
near Milburn the older rocks (altered greywacke) are clearly seen to be much fractured 
and to be thrust over the gravels that are believed to be the stratigraphical equivalents 
of the Bluespur " cement." A similar shattered state of the altered greywackes is to 
be seen at the Milton brickworks. These two observations go far to prove at least that 
thrust-movements have been of much importance in this region, and when combined 
with the suggestions offered by the physiographical peculiarities of the district it 
appears that there is much evidence in favour of the idea that thrust-movements 
from the east have had great influence in shaping the main features of the surface 
of this part of New Zealand. 



27 



CHAPTER V. 



TUAPEKA SERIES. 



Introduction . . 
Historical Account 
Petrography . . 

Baiclutha 

Stony Creek 
Progressive Metamorphism of Rocks 
Structure 

Age .... 

Chemical Composition of the Rocks 
Economic Geology of Tuapeka Series 
Auriferous Lodes 

O.P.Q. Lode 

Canton Lode 

Sandagger's Lode 

Nuggety Gully Lode 

A B (; Lode 

Cemetery Lode 

Bella Lode 



Page 
27 

27 


Economic Geology of Tuapeka Series — ctd. 
Auriferous Lodes — continued. 


Page 


28 


Cox's Lode 


39 


29 
29 


Cosmopolitan and adjoining Lodes . 
Fulton's Lode and Neighbourhood . 


40 
40 


33 


Lodes on Lammerlaw Mountains 


40 


34 


Canada and Ocean View Lodes 


41 


35 


Gabriels Gully Lode 


41 


36 
37 


Gray's Gully 

Simpson's and Burnt Creek Veins 


42 
42 


37 


Origin of the (Jold . . 


42 


37 


Antimony Lode, Lammerlaw Mountains 


43 


38 


Waitahuna Copper Lode 


44 


38 
38 


Origin of the Copper 
Cinnabar . . 


44 
44 


39 
39 


Origin of the Cinnabar 
Scheelite 


44 
45 


39 


Origin of the Scheelite 


45 



Introduction. 

The older rocks of the Tuapeka district which occur throughout the area described 
have, almost without exception, been classed in two or more geological ages by those who 
have examined them, mainly because of the different extent to which rocks in various 
parts of the district have been affected by metamorphic action. For reasons that will be 
explained shortly it is here considered advisable to class both metamorphic and 
relatively unchanged rocks in the same series. This follows the practice adopted 
with the Arahura Series in Bulletin No. 1 of the Geological Survey. This does not 
necessarily imply that the Tuapeka Series and the Arahura Series arc definitely of 
the same age, though in the opinion of the author this is probably the case. 



Historical Account. 

S. H. Cox* in 1878 was the first geologist to report on this district. There has 
been practically no report since that time, though the district was included in the 
very large area examined in 1893 by McKay. f In this report, however, McKay 
makes veiy little detailed reference to the rock-series in the Tuapeka district. Morgan J 
in 1914 also issued a brief general report on this district. 

Though not the subject of specific geological reports, the district lias had its 
structure represented on many occasions in the geological maps issued by several 
geologists. The following is a brief recapitulation of the indications given in such 
maps : — 

Hector : Sketch-map of the Geology of New Zealand, 1869. The whole Tuapeka 
district, with the exception of patches of " cement " and other younger rocks, 
is classed as Palaeozoic. It is said to consist of foUated and contorted 
schists with mica, chlorite, quartz, &c. Auriferous. The area of these rocks 
extends to the south of Baiclutha. 



*Cox, S. H. : "The Tuapeka Cements." Rep. Geol. Explor. during 1878-79, No. 12, 1879, pp. 42. 
et seq. 

t McKay, A. : " Older Auriferous Drifts of Central Otago." Mines Reports, C.-4, 1894. (Government 
Printer.) (Second ed., Wellington, 1897.) 

{Morgan, P. G. : "The Lawrence-Waipori District." Eighth Ann. Rep. Geol. Surv., 1914, pp. 154-156. 



28 

Hector, 1873: Geological Sketch-map of New Zealand. Wellington. The rocks 
are coloured as foliated schists to which no age is as.signed. The foliated 
schists extend as far as the Clutha River. 

Hutton : " Geology of Otago." Dunedin, 1875. The first three of Hutton's formations 
are included in the Tuapeka district. Wanaka — Lower Silurian(?), at Waipori ; 
Kakanui — Upper Silurian(?), Lawrence as a centre ; Kaikoura — Carboniferous(?), 
beginning ten miles south-west of Lawrence ; Maitai^ — Triassic, at Balclutha. 
The division-lines between these series of rocks are generally directed from 
north-west to south-east. 

Cox, in Geological Reports, 1878-79, classes the rocks as Lower Carboniferous 
and foUated schists. 

Hector, 1883 : Sketch-map of the Geology of New Zealand. Included in the 
Reports of Geological Explorations, 1883-84. A division-line between two 
formations extends from a point twelve miles south-west of Lawrence to eight 
miles south-west of Havelock, and thence south-eastward to the Tokomairiro 
Plain. The rocks to the south-west of this line are coloured Lower Carboniferous 
to Lower Silurian. North-west of the line the rocks are indicated as foliated 
schists to which no age is assigned. This map was reissued with the Reports 
of Geological Explorations during 1890-91. A reprint of the same map dated 
1885 was included with the " Outhne of the Geology of New Zealand," printed 
for the Indian and Colonial Exhibition of London in 1886. 

McKay, 1894, and second edition, 1897 : " Older Auriferous Drifts of Central Otago."' 
Two main rock-divisions are distinguished — (1) Carboniferous and Devonian; 
(2) Metamorphic schists, probably of Silurian age. The dividing-line extends 
from five miles south-west of Lawrence to one mile south of Havelock (Wai- 
tahuna), whence it extends eastward to the Tokomairiro Plain. The metamorphic 
schists are subdivided into : (3) Upper schists— grey flaggy arenaceous schists, 
sometimes with quartz folia, but these are not characteristic of the rocks 
south-west of Lawrence ; (2) middle schists — soft silky mica-schists, with or 
without their somewhat regular laminae of quartz — from Lawrence to Wai- 
pori ; (1) lower schists — mica-schists, calcareous, strongly foliated, with 
elliptical masses of quartz ; sihceous and chloritic schists, with abundance of 
magnetite in crystals or massive — north of Waipori. 

Park : " Geology of New Zealand," 1910. The whole district is coloured as Car- 
boniferous to Ordovician, while the Lammerlaw Mountains are coloured as 
Cambrian. 

Marshall : " Geologj- of New Zealand," 1912. All the rocks are classed in the 
Maitai System of Mesozoic age. The dividing-line between the metamorphic 
and relatively unchanged rocks passes eight miles south-west of Lawrence and 
one mile south-west of Havelock, and thence eastward to the Tokomairiro 
Plain. 

Petrography. 

At Balclutha the rocks in hand-specimens are moderately coarse sandstones without 
di-stinct division-planes of any kind. There are also fine shales of a greyish colour. At 
Stony Creek, five miles to the north, the grains of sand have become less distinct, and the 
colour has changed from the dark grey of the Balclutha rock to a light grey. There 
are still no regular division-planes to be seen. A type of rock of precisely the same 
nature occurs at the Tuapeka mouth and for two miles farther up the valley of the 
Clutha River. At the top of the Manuka G<n'ge a distinct flaky character has already 
developed, and this same character is distinct some six miles down the Tuapeka 



Plate V. 





Fig. 1. 



Fig. 2. 





Fi(!. 3. 



Fig. 4. 



Fig. 1. Greywacke, Balclutha, Ordinary Light. 
Fig. 2. Greywacke, Balclutha, Crossed Nicols. 
Fig. 3. Rock from Stoxy Creek, Ordinary Light. 
Fig. 4. Rock from Stony Creek, Crossed Nicols. 



Geol. Bull. So. 19.] 



[To face page 28. 



29 

valley from Lawrence. At Lawrence and Havelock this flaky character has become much 
more pronounced, and is often associated with a distinct interlamination of quartz, though 
this is not sufficiently frequent to justify the use of the term " schist." This type 
of rock is continued generally for six miles north-east of Havelock, and thence to the 
upper end of the Waipori Gorge. All the rock to the north of this line contains 
distinct laminations of quartz and mica, and is correctly called " mica-schist." The 
line between the mica-schist and the flaky rock that joins it to the south-west is 
purely empirical. There appears to be a uniform gradation from one tyj)e to the 
other, with a complete series of transitional forms. The gradual change into the meta- 
morphic structure was clearly recognized by Hutton, who wrote of his Kakanui forma- 
tion, " This formation is quite conformable to and passes insensibly into the Wanaka 
formation."* He considered, however, that the mapping showed an unconformable 
relation between the Kaikoura and Kakanui formations, which have their contact-line 
to the south-west of Lawrence. In other parts of New Zealand a similar gradation 
and transition has been recorded in the rocks of the Arahura Series. 

The typical sandstone is often interstratified with shales. As is usually the case, 
these fine-grained sediments have suffered the motamorphic changes more completely than 
the coarser ones. At Glenore there is a quariy in the fine-grained rocks, which are 
there completely changed into phyllite, while the neighbouring sandstones have suffered 
little apparent change. In several places, notably the lower part of the Tuapeka valley, 
the rock consists of irregular patches of phyllite embedded in greywacke. This is 
quite frequent in the greywackes in various parts of New Zealand. 

The microstructure of the rocks shows quite as definite a gradation as is displayed 
in the hand-specimens. Within the strict limits of the Tuapeka district no unaltered 
type was found in situ, though some of the boulders in the auriferous conglomerate 
are unchanged greywacke. It is therefore necessary to describe a specimen from 
Balclutlia in order to give an idea of the nature of the rock which, in the opinion 
of the author, is the general tj^e of the district, though throughout it has been con- 
siderably changed and, over a considerable area, has been entirely converted into a 
schist by metamorphic action. 

Balclutha. — The greywacke near Balclutha is a medium-grained sandstone which 
consists mainly of rounded fragments of feldspar. The greater number of these are 
untwinned, and appear to be an acid alkaline tj'pe. The feldspar-grains are not in 
sufficiently close contact with quartz to allow of a comparison of refractive indices. 
These untwinned feldspar crystals are always clouded with a number of alteration- 
products. These are always extremely small and perfectly clear. No definite shape 
is prevalent, but the colourless character, high birefringence, and apparently straight 
extinction suggest that they are muscovite. 

There are several grains of twinned feldspar, and the angle of extinction shows 
that they have the composition of andesine. These grains are perfectly clear and 
free from alteration. Grains of quartz are moderately common ; they are small and 
angular. Augite is not uncommon ; its colour is very pale green, and it is quite fresh. 
It appears to have been derived from a volcanic lava. Occasional grains of serpentine 
or chlorite are to be seen, which suggest the presence of some ferro-magnesian mineral 
in the original sand. Many grains of magnetite are present, and there are some small 
fragments of volcanic rock, usually glassy and containing small microlites of feldspar. 

Stony Creek. — In this locality, situated six miles north-east of Balclutha, there is a 
good exposure of unweathered rock. The granular nature of this rock is quite apparent 
witb ordinary light, but the majority of the grains are much more cloudy. Between 

* "Geology of Otago," 1875, p. 33. 



30 

crossed nicols a great change is to be observed. Quartz-grains, as before, are few, 
and they are quite unaffected ; and the same remark apphes to the few grains of 
twinned feldspar, which are quite clear. The other minerals, however, have undergone 
great changes. Those that undoubtedly represent the alkaline feldspars are now so 
altered that none of the original feldspar appears to remain. The alteration-products 
are far more developed ; and muscovite is in much larger crystals, and with it there 
is some very finely granular quartz, though this is more conspicuous in the fine paste 
between the larger grains. No indication of rock-flow can be seen, though within a 
single altered grain the mica seems to have parallel arrangement. The magnetite and 
augite appear to be in much smaller quantity than in the Balclutha specimen. Some 
grains of magnetite are present in an unaltered state, and the augite may be represented 
by the small quantity of epidote that is to be seen. 

The rock which occurs at the Tuapeka mouth is in quite the same condition as 
that described from Stony Creek. Here again there is no trace of any kind of crush 
or of flattening or distortion of the grains of sand, nor is there any parallel arrange- 
ment of the minerals. A small vein of calcite traverses the section. A specimen obtained 
from the bank of the Clutha River two miles above the Tuapeka mouth shows a shght 
pgfrallel arrangement of the secondary mica. It contains also an unaltered grain of 
augite, and another grain apparently of augite which has been completely changed 
into epidote. 

A specimen obtained from a small quarry by the side of the railway-line, three 
miles west of Milton and two miles south-east of Glenore, to ordinary macroscopical 
examination appeared a typical greywacke, though perhaps with a suggestion of shaly 
parting. The microscope shows a decided advance towards the metamorphic facies. 
The altered feldspar-grains have now become much less transparent, and they are dis- 
tinctly compressed ; the mica flakes which have become developed in them are elongated 
parallel to the direction of the compression of the feldspars, and have a very general 
parallel extinction in this direction. The small quartz-grains which can now be dis- 
tinguished in the altered feldspar have, however, no general extinction direction. Three 
grains of triclinic feldspar that can be seen in the section are quite unaltered and fresh. 
The quartz-grains have not been compressed Uke the altered feldspars, but they have 
finely notched borders, a phenomenon that certainly signifies a chemical attack. The 
fine notching is possibly more noticeable in the direction of the parallel structure of 
the rock than at right angles to it, but this observation is somewhat doubtful. 
It can, however, be definitely asserted that the action is not more pronounced in the 
direction at right angles to the elongation of the altered feldspars and the secondary 
mica than in the direction parallel to them. Frequently mica flakes project into 
the minute angular notches of the quartz, but in other cases the quartz appears to be 
fractured. 

There is considerable evidence of the movement of the other elements of the rock 
relative to the quartz-grains. The mica flakes in particular often bend round the 
angles of the quartz, thus producing the appearance of flow structure. The grains of 
quartz show a shght amount of undulose extinction, but it is not prominent. 

At Glenore, some two miles to the north-west, the original quartz-grains have 
become reduced to quite small dimensions, and their margins are still more notched 
and irregular. The other elements of the rock are not noticeably coarser, but the 
boundaries of the original feldspar-grains, which were presumably once present, are now 
entirely lost. A few grains of triclinic feldspar .still remain, and are not altered. 

At Mount Stuart, a mile farther to the north-west, the quartz-grains have almost 
entirely disappeared, except that there are clear patches of three or four interlocked 
quartz-granules which seem to have been produced from the original grains. Small 



31 

veins or lenticles of interlocking quartz-grains have now appeared, and associated with 
the quartz in these lenticles is some albite. 

At the head of the Manuka Gorge, one mile farther to the north-west, the rock 
has become in general quite schistose. There is, however, a bed of rock here in which 
residual grains of quartz and tri clinic feldspar are still large. The former, however, 
has deeply notched margins and shows distinct undulose extinction, while the triclinia 
feldspars have also been vigorously attacked ; some epidote as well as mica has been 
formed within them. It appears that this rock was originally a coarser type of sandstone 
than the others. All the rest of the rock has slightly coarser mica and interlocking 
quartz-grains which show flow structure around the resistant quartz granules. It is 
quite impossible to recognize any structure that in itself enables one to state that 
the elongated lenticles of fine interlocking quartz-grains and minute laths of sericite 
are derived from original feldspar-grains. Yet, to one who has examined the series 
of sections from Balclutha to this point there can be no doubt that this is their 
origin. The boundaries of the grains have now become almost completely lost, 
though it appears that the length of these altered grains averages about four times 
their breadth. The quartz-grains have certainly suffered considerable attack through 
some chemical process. In this rock it can be definitely stated that the quartz is 
notched in the direction of the elongation of the altered feldspar-grains, and it is on 
these sides of the grains that the reduction of the quartz is in most rapid progress. 
This reduction is not in the nature of granulation or of recrystallization, but apparently 
is associated with the formation of chloritoid nadnerals or of sericite, which, in the 
direction of feldspar-elongation, project like needles into the quartz. 

The conclusion that the quartz suffers more rapidly in the direction of the rock- 
flow is supported by the general form of the residual grains in a section. The average 
quartz-grain contained in this rock has a larger dimension across the flow than parallel 
to it. No defuiite instance of granulation can be seen, though where grains of quartz 
have a considerable elongation at right angles to the flow some angular small detached 
particles are in some cases to be seen near these ends. It is, however, not certain 
that these detached grains have any special relation to the large grain alongside 
them. The fact that there is a multitude of large and small grains of quartz that 
show no trace of this tells against the suggestion offered by these very occasional 
observations. There is a certain amount of flow structure round the quartz-grains, 
but this is not very pronounced. The small interlocked quartz-grains that have 
developed from the original feldspar have an average diameter of about 0-01 mm., 
a size that has not increased much since the development of these grains was first 
distinct. The rock is now quite similar in appearance and structure to a porphyroid, 
but as these rocks are always described as developed from acid igneous rocks the term 
should probably not be applied to the present specimens, which have developed from 
sedimentary types. 

Five miles from Manuka Gorge, at the junction of the roads from Waitahuna 
Gully and from Waipori to Havelock, a cutting in still more altered rock is found. 
Here there is distinct foliation, and in the general mass of the rock all trace of its 
original structure and composition is absolutely lost. There are long lenticles of 
interlocked quartz-grains now 0-07 mm. in average diameter. There are also lenticles 
of elongated mica laths and patches where granular epidote is abundant, but in small 
grains not more than 0-02 mm. in diameter. Though the general rock-change is now 
so great there are still a few residual grains. Most of these consist of triclinic 
feldspar. One in particular cut at right angles to the brachypinacoid has an extinction 
angle of 16°, and is thus probably oligoclase-andesine. It is somewhat cloudy, and 
numerous grains of epidote have been formed within it. The direction of elongation 



32 

of this grain is nearly at right angles to the foliation of the rock. The twinning- 
plane, wliich is parallel to the elongation, is slightly bent, and round the ends of 
the grain there is distinct flow structure, though here, as with the quartz crystals 
in previous sections, the mineral is yielding to the metamorphic influences to a greater 
extent along the plane of foliation than at right angles to it. This rock is distinctly 
a quartz-mica-schist. 

At a small cutting two miles farther to the north-west another specimen was 
obtained. Except for a slightly irregular streaky structure, there is nothing to indicate 
the original granular nature of the rock. Almost the whole rock now consists of 
fine interlocking grains of quartz, with an average diameter of 0-02 mm , and a multitude 
of minute mica laths with their long axes all in the direction of the streakiness of 
the rock. There are in places many minute epidote crystals not regularly oriented. 
A distinct lenticular arrangement of interlocked quartz crystals is noticeable in some 
portions of the rock, but it can hardly be said in general that there is as yet any 
di.stinct development of foliation. A few original qxiartz-grains still remain. The 
arrangement of the mica laths and other mineral elements of the rock round them 
is a clear proof of some flow. The grains show very slight strain -shadows. In one 
instance there is a small amoimt of eye structure and granulation, but this is unusual. 
Again, the quartz crystals show more sign of reaction to the metamorphic agencies in a 
direction parallel to the streakiness of the rock than at right angles to it. This 
rock stOl has the appearance and structure of a porphyroid. 

A rock-specimen taken from the quarry on the right-hand side of the road at 
the entrance to Gabriel's Gully shows no trace of original .structure. It is composed 
of thin laminae of quartz, which consist of small interlocked crystals, and laminae 
of micaceous minerals with quartz. There are occasionally small grains of epidote. 
The laminae are somewhat bent and contorted. 

One mile from Lawrence, on the road to the Bluespur, there is a cutting opposite 
the sluice-gate for the water-supply for the flour-mills. The rock is finely schistose 
in hand-specimens, but in sections shows the presence of many residual quartz- 
grains. Here, as before, the quartz-margins are penetrated by the sharp ends of laths 
of mica. Distinct flow structures round the quartz-grains occur nearly everywhere. 
The quartz-grains are now not simple. In many cases angular fragments occur 
with the main grain. These angular fragments are in close contact with the grain, 
and have irregular margins. They are noticeably free from the small inclusions seen 
in the large grain, and the suggestion is made that they are recrystallized portions. 
The angular fragments are foimd with only a few of the quartz-grains, and there 
are never more than two or three of them. They are as frequent on those margins of 
the grains which are parallel to the schistosity as on the margins at right angles to 
it. They do not appear to be separated as the result of the action of pressure. 
A few of the smaller grains have undergone this recrystallization to such an extent 
that typical eye structure has developed. 

The road-cutting at the south-east end of the Bluespur conglomerate exposes 
a distinctly schistose rock. The locality is two miles north-east of the previous one. 
Epidote is now quite abundant, and some of it is in large grains, many of which 
have distinct eye structure, and around nearly all of them flow structure is distinct. 
There is also a large quantity of fine granular epidote in the rock, and this with mica 
and quartz constitutes the whole of the minerals. The schistose structure, which is evident 
enough in hand-specimens, becomes even more distinct in microscopic preparations, 
and the rock is at once seen to be foliated with bands of nearly pure quartz con- 
sisting of interlocking grains. These alternate with other bands, in which mica and 
epidote are the more characteristic minerals. 



Platk VI. 





Fig. 5. 



Fig. 6. 





Fig. 7. 



Fig. 8. 



Fig. .5. Rock at East Extraxce to Tokomariro Gorge. Section cut Parallel to the Flattening. 

Ordinary Light. 
Fig. 6. Same as Fig. 5. but seen between Crossed Nicols. 

Fig. 7. Same Rock as Figs. 5 and 6, but Section cut at Right Angles to the Shaly Fracture. 
Fig. 8. Rock from Manuka Tunnel, cut Parallel to the Shaly Fracture. 



Qed. BvM. A'o. 19.] 



[To face page 32. 



33 

At Waipori the schist is quite typical, and consists of quartz lenticles often 3 cm. 
across. The lenticles consist of interlocked grains of quartz as much as 04 mm. in 
diameter. Associated with the quartz there is a good deal of albite, recognizable by 
its extinction angle and low refractive index. There is a little colourless mica, appa- 
rently typical muscovite, but it is in much less quantity than chlorite, recognizable 
by its pale-green colour and low birefringence. Epidote is absent in all the sections 
made. 

Progressive Metanwrphism of Rocks 

The petrological description of the various typen ot rocks shows clearly that they 
exhibit progressive metamorphism when followed from south-east to north-west. Certain 
features of this series of structural changes are worthy of special notice. 

1. The mineral-grains in the original greywacke rock have suffered very slightly 
from stress. The quartz-grains have in the great majority of cases failed to acquire 
strain-shadows. Even when they have this character it is slight. There are only a 
few doubtful cases of marginal fracture of any grains of quartz, and none of cata- 
clastic structure, and granulation is somewhat uncertain. 

2. The original quartz-grains have suffered from chemical action. This has 
occurred to a greater extent in the plane of the platy structure of the rock than 
at right angles to it. The action is evidenced by the notched margins of the grains 
of quartz in this plane and the projection of the laths of secondary minerals, such as 
mica, into the quartz-grains. 

3. The quartz does not directly recrystallize as such except in a few doubtful 
cases, but the greater part of the silica appears to enter into combination with other 
substances and to form secondary minerals, mainly mica. At the same time the 
crystallization of quartz in interlocking grains may be in progress in another part of 
the rock. 

4. On a general average, after the rock has become distinctly schistose the residual 
quartz-grains have a larger diameter at right angles to the plane of schi.stosity than 
parallel to it. . 

5. The original grains of alkaline nionoclinic feldspar suffer change with great 
readiness, and before any general structural change is noticeable they are altered into 
very fine granular quartz and a micaceous mineral (sericite ?). 

6. These altered secondary substances apparently undergo constant I'ecrystallization. 
The individual interlocking granules become larger and larger. At the same time 
the mica laths are all oriented in the same direction, which is parallel to the plane 
of schistosity. The original grains, now converted into aggregates of minute interlocked 
granules of quartz and laths of mica, become greatly elongated in the direction of 
the long axis of the mica laths. This elongation is associated with the gradual 
extension of the component granules, and may reasonably be regarded as a result 
of recrystallization . 

7. This recrystallization of regularly oriented mica laths and the elongation of 
the altered feldspathic grains is the immediate cause of the appearance of schistose 
structure as seen in hand-specimens of the rock. 

8. The original grains of the triclinic soda-lime feldspars are very slightly subject 
to change, and still remain but slightly clouded by development of minute crystals 
of epidote, even when the original quartz has disappeared as a result of chemical 
attack and when the rest of the rock has been completely recrystallized and has 
acquired a complete schistose appearance in hand-specimens and in microscopic pre- 
parations. 

9. Epidote is not conspicuous until a schistose structure has become pronoimced. 
It then forms, for the most part, rounded grains. 

3 — Tuapeka. 



34 

From these facts the following conclusions seem to follow : — 

10. It is evident that the schistose structure of the rocks in the north of this 
district is not due to the direct mechanical effect of great pressure. 

11. It appears that chemical action has been greatly stimulated by some external 
general cause. 

12. This general cause is probably mechanical pressure, for the recrystallization 
of all the minerals is clearly related to some influence which causes a regular orientation 
of the secondary crystal-grains which are formed. 

13. No petrological observations were made that appear to give any basis for an 
estimate as to the cause of this pressure or as to its intensity. 

14. The series of specimens examined indicate that the schists of this district 
were almost certainly derived from greywackes of similar composition throughout. 

Plates V-VIII, containing figs. 1-15, illustrate the microscopic characters of the 
rocks described on the preceding pages. The earlier figures were purpo.sely selected 
from rocks of a coarse grain, because they show most clearly the progressive nature 
of the change as the rocks are followed in a northerly direction from Balclutha. The 
schist from Bluespur, illustrated by figs. 13 and 14, seems originally to have lieen a 
finer-grained rock than those shown in the preceding figures. 

Structure. 

The great disturbance to which this series of rocks has been subject and the 
extent to which their characters have been destroyed by metamorphic changes have 
rendered the interpretation of the structure a matter of peculiar difficulty. Generalized 
attempts to represent this structure have been made by at least three geologists. 
Hector issued with his general geological maps of New Zealand sections across the 
south part of the South Island. These indicate for the most part a simple anticlinal 
structure, but as they pass a considerable distance to the north of the Tuapeka district 
they do not require any special consideration here. 

Hutton* drew another section which passed practically through the Tuapeka region. 
The whole of the district is represented as forming the eastern limb of an anticline 
with a uniform dip of about 30° to the east. 

McKayl gave a generalized section in which he represents the district as con- 
stituting the eastern limb of an anticline, which, however, shows some secondary 
folds, and also another section which refers more particularly to the Tuapeka district. 
The latter figure apparently makes no attempt to represent the structure of the 
Tuapeka Series, but only the relation of the series to the auriferous deposits which 
rest on them. 

It has been generally thought that the plane of foliation coincides with the 
stratification -planes. This was originally stated by HuttonJ in the following words : 
" As the changes in the lithological character of these rocks take place at right angles 
to the plane of foliation, it follows that the foliation coincides with the original plane 
of bedding. This is further confirmed by the general geological structure of the 
district, for as a general rule the plane of foliation dips towards that portion of the 
next youngest formation that lies nearest." This opinion appears to have been accepted 
without question by later geologists. Rickard,§ however, is the only subsequent author 
who explicitly restates it. 

* Hutton, F. W., and Ulrich, G. H. F. : " Geology of Otago," plate vi, section 2. Dunedin, 1875. 
t McKay, A. : " Older Auriferous Drifts of Central Otago." Mines Report, C.^, 1894 (2nd ed., 1897), 
figs. 1, 7. 

J Hutton, F. W., and Ulrich, G. H. F. : " Geology of Otago," 1875, p. 31. 
§ Rickard, T. A. : Trans. Amer. Inst. Min. Eng., vol. xxi, 1892, p. 413. 



35 

In general it is probable that this is correct, though there is usually so little 
change in the lithological nature of the rock, and the stratigraphical planes are so 
obscure, that it is impossible to make any definite statement on the subject. At one 
locality situated to the south-east of the district it was found that the plane of 
stratification did not correspond with the plane of slaty parting, which certainly 
gradually develops into the foliation-plane throughout the district. This locality is in 
a cutting on the east side of the road from Milton to Balclutha, about one mile north 
of the Stony Creek crossing. Here the stratification is seen in a fine mudstone to 
have a strike of 132° and a dip of 27° to the south-west, while the slaty parting has 
a strike of 51° and a dip of 10° to the south-east. It is possible that this is an 
exception, for definite signs of stratification could not be found elsewhere, and in 
general there appears to be a correspondence between the planes of foliation and the 
planes of change in lithological character, though this is so slight as to give little 
indication . 

During the progress of the survey it was found to be impossible to find any other 
planes than those of foliation on which to make observations of strike and dip. More 
than two hundred of these were made. In many localities the dip and strike change 
completely within a few yards, and much care had to be exercised to obtain the 
average measurements in any one locality. In general it may be said that in the 
western part, on the banks of the Molyneux River, the strike is nearly due north with 
an easterly dip gradually bending to the north-east, with a south-easterly dip in the 
region to the south of Lawrence. North of Lawrence, however, the strike becomes 
north-west with a south-west dip, which gradually changes to a westerly strike with 
a southerly dip at Waipori. This does not appear to indicate any definite structure. 
Moreover, the changes in dip and strike are frequent and complete, and at the 
same time the average dip is so low that too much importance should not be attached 
to it. The only generalization that seems permissible is the statement that the dip 
almost throughout has a southerly tendency, which may indicate that the great 
north-west - south-east anticlinorium of the south of New Zealand has a pitch towards 
the south-east. It also suggests that the rocks of the Waipori region occupy a 
lower position in the series than those of Lawrence and portions of the district farther 
to the south. 

A.GE. 

The age of the Tnapeka Series is a question about which a great variety of 
opinion has been expressed. Briefly stated, it can be said that every age from pre- 
Cambrian to Trias-Jura has been ascribed to some part or other of the series, not 
specifically as developed in this district but at least in adjacent districts, the rocks 
of which have been correlated with those of the Tuapeka Series by all geologists. 

No fossil remains have yet been found in this series — at any rate, in the Tuapeka 
district. The nearest points' at which fossils have been found are the Kaihiku Gorge 
and Nugget Point, twenty miles distant in a southerly direction. In these localities 
the rocks are greywackes, in which the grains of feldspar are perfectly fresh and 
unweathered. Petrologically, the freshness of the feldspar alone distinguishes them 
from the rocks at Balclutha. So far as lithological evidence is concerned, the rocks 
would reasonably be placed in the same series. Stratigraphically, the rocks are 
highly inclined in both localities, but the strike is somewhat different. The 
importance of this should not be exaggerated, for the localities are twenty miles 
distant from ea<;h other, and the exact structure of the intervening country is not 
known. In fact, divergences of strike in one and the same rock-series are common 
throughout New Zealand. Stratigraphically, there is no strong reason to separate 

3* — Tuapeka. 



36 

the rocks at Balclutha fiom those at Nugget Point, and they have previously been 
associated, notably by Hutton. 

As the age of the Nugget Point and of the Kaihiku Gorge rocks is not older 
than the Middle Triassic, there seems to be no reason to place the Balcluth^ rocks in 
a division of greater age than the Early Mesozoic. 

It has been shown that the various rock-types of the Tuapcka Series, even ui eluding 
the schistose types, are clearly derivable from such a greywacke as that at Balclutha, 
and no break of any kind has been distinguished between them. It is therefore 
proposed to place the rocb of the Tuapeka Series, whether schistose or not, in the 
Early Mesozoic portion of the Trias-Jura formation. The classing of mialtered 
sediments and schistose rocks in the same stratigraphical series has already been done 
by Bell and by Morgan in Westland, where the Arahura Series includes both schists and 
greywackes. 

Chemical Composition of the Kocks. 

The following analyses give the chemical composition of the rocks in their various 
stages of metamorphism. In general it may be said that the analyses show no very 
marked feature, and though the different rocks exhibit a great variation of composition 
this is not greater than would reasonably be expected in a series of greywackes. 





A. 


B. 


c. 


D. 


E. 


F. 


G. 


Silica (SiOa) .. 


59-50 


63-90 


67-60 


71-00 


72-10 


68-20 


70-02 


Alumina (AI2O3) 




20-84 


19-46 


17-99 


17-87 


17-88 


16-63 


5-67 


Ferric oxide(Fe203) 




2-26 


3-07 


3-88 


2-71 


1-01 


0-04 


3-68 


Ferrous oxide (FeO) 




6-03 


2-32 


2-19 


1-09 


2-72 


3-14 


3-38 


Lime (CaO) 




3-55 


3-10 


2-88 


1-52 


2-32 


2-45 


7-80 


Magnesia (MgO) 




1-78 


0-37 


0-36 


0-41 


0-43 


1-30 


1-20 


Soda (Na^O) . . 




0-99 


5-51 


1-69 


1-16 


1-22 


2-43 


0-78.. 


Potash (K2O) . . 




1-41 


1-20 


1-40 


1-33 


1-35 


2-33 


1-22 


Loss on ignition 




3-20 


1-48 


2-20 


1-90 


1-88 


2-25 


7-12 






99-56 


100-41 


100-19 


98-99 


100-91 


•• 


100-87 



(A.) Greywacke, Balclutha. 

(B.) Grey^vacke, near Glenore. 

(C.) Greywacke, Tuapeka Mouth. 

(D.) Altered greywacke, Molyneux River. 

(E.) Altered greywacke, Molyneux River. 

(F.) Greywacke, Mmigo River (N.Z. Geol. Surv., Bull. No. 6, p. 95). 

(G.) Mica-schist, Macrae's. (Finlayson, Trans. N.Z. Inst, for 1907, vol. xl, 
1908, p. 108.) 
Of these rocks the specimens C, D, and E show a gradually advancing meta- 
morphism, though it does not proceed far. It was not foimd possible to trace any 
rock sti'atum along the strike from the unaltered zone to the schistose area. It 
was therefore impossible to test the accuracy of the application of Leith's theory* 
of redistribution of chemical constituents as the metamorphic changes progress. The con- 
fused nature of the stratigraphy, the surface covering of clays, and the weathered 
nature of the rocks will probably prevent such a research for all time in this area. 
The analyses of a series of specimens from different strata in a sedimentary series 
affords no basis for a chemical comparison of this nature. 



* Leith, C. K., and Mead, W. J. : " Metamorphic Geology," 1915, p. 271. 



Plate VII. 





Fig. 9. 



Fig. 10. 





Fig U. 



Fig. 12. 



Fig. 9. Rock from Manuka Tunnel, cut at Right Angles to the Foliation. 

Fig 10. Same as Fig. 9, but seen between Crossed Nicols. 

Fig. 11. Rock at Sluice Gate, between Lawrence and Bluespur, cut at 

Foliation. Ordinary Light. 
Fig. 12. Same as Fig. 11, but viewed between Crossed Nicols. 



Ordinary Light. 



Right Angles to the 



Geol. BuU. So. 19. 



[To face page 36. 



Plate VIII. 





Fig. 13. 



Fig. 14. 




Fig. 1.-). 



Fig. 13. Schist, Bluespur. Section cut at Right Angles to the Foliation. Ordinary Light. 
Fig. 14. Sa.me a.s Fig. 13, but seen between Crossed Nicols. 

Fig. 1.5. Schist from Entrance to Lammerlaw Creek Gorge, Waipori. Section cut at Right Angles to 
the Foliation. 



Geol. Bull. So. 19.] 



[To face page 36. 



37 

Economic Geolory of Tuapeka Series. 

There is no doubt that the source of all the alluvial gold is to be found in 
the Tuapeka Series. However, the amount of gold that has been obtained directly 
from this series is small, though several auriferous-qaartz reefs are known and have 
been worked to some extent. Most of these, inifortunately, are quite small. In 
addition to gold, several other metals occur in ore-bodies in the more metamorphic 
members of the series. These metals are copper, antimony, mercury, tungsten, and 
manganese. No large quantity of any of these ores has yet been mined. 

Auriferous Lodes. 

Auriferous-quartz lodes have been worked mainly in the vicinity of Waipori. 
The O.P.Q.* lode. Canton, Nuggety Gully, Fulton's, Bella, Cox's, and Cosmopolitan 
have all been the scene of activity, but at the present time the O.P.Q. is the only 
one on which any work is being done. 

O.P.Q. Lode. — This lode has an extended history, for the first portion of which I 
an indebted to Mr. R. Webb, of Waipori. It was discovered by a party of twelve 
Shetlanders in 1861, and for some time it was worked by them with fair results. 
Townspeople replaced some of the Shetlanders, and small shafts were sunk, steam- 
power being used, but the cost of this soon proved excessive. In 1868 Burrell 
worked the mine for a short period, using steam-power. In 1875 Hill and Beal 
worked on the lode for about two years, using water-power. A block of stone near 
the surface was taken out, and this paid all expenses. In 1888, it is stated in the 
New Zealand Mining Reports, Porter and party were working the mine, and had 
crushed 700 to 800 tons for a yield of Sdw^. to 14 dwt. per ton. Five other parties 
were said to be working on the same line of lode. In 1894 Ritchie and other parties 
were reported to be working on the line of lode, but with no success. In 1898 
the mine was again manned, and some twenty-six men were employed. A shaft 
had been sunk to a depth of 150 ft., and a level had been driven for a distance 
of 450 ft. In the following year 170 tons were treated weekly foi- a total yield 
of 851 oz. Ill 1900 the reef was reported to be 10 ft. wide at the lowest level, 
285 ft. from the surface. The average yield is given as 8^- dwt. pei' ton, and 
the gold won during the year was worth £9,000. In 1903, however, the work 
stopped. 

Nothing further was done luitil 1915, when a prospecting drift was begun at the 
north-east end at a low level. The lode strikes 160° and dips about 50° to the 
east. It traverses the typical mica-schist of the district, which strikes 140° with a 
dip of 25-54° to the north-east Within the lode the quartz-bodies are not con- 
tinuous, and the walls of the lode are not well defined. The greater part of the 
auriferous belt is locally termed " reef formation," and consi.sts of much cmshed and 
contorted mica-schist. The thickness varies, approaching 20 ft. in places. The quartz- 
bodies, which are extremely inegular, occur most frequently near the foot-wall, and 
there may occasionally be two parallel qaartz-bodies. For a great length (850 ft.) 
along the present drift there are, however, no quartz-bodies of any size, and such 
as there are carry little gold. The lode has been prospected for a distance of a 
mile and a half along the strike, and over the greater part of this distance payable 
quartz has been extracted. 

The various companies which have taken over the mine appear to have done 
too little prospecting and development work. When the particular quartz-body on 
which they were working was exhausted there were no new ore-bodies in sight. 

♦The letters O.P.Q. are the initials of the first three words in the title Otago Pioneer Quartz-mining 
Company. 



38 

The quartz near the surface was rusty, and in places was extremely rich. At 
greater depths it was of a dark coloiu', and distinctly seamed with pyrite and arseno- 
pyrite. The method of treatment employed for the ore was evidently misuitable, for 
the tailings assay 13s. 9d. and £1 Is. 6d. per ton in different places. 

The irregular occurrence of ore-bodies in this lode-formation shows that any company 
that undertakes its exploitation must be prepared to prospect and develop vigorously. 
It has been suggested that the O.P.Q. formation underlies the Waipori Flat, and it is 
said that it can be distinguished on the north side of the valley. While it is probable 
that the formation does continue beneath the gravel of the valley, no definite con- 
tinuation on the north side could be seen. 

Descriptions of the O.P.Q. Mine, written when mining was in progress and the 
workings were accessible, will be found in the " Geology of Otago," by Hutton and 
Ulrich, p. 197 (Dunedin, 1875), and in Trans. Amer. Inst. Min. Eng., vol. xxi, 1893, 
p. 411 ("The Goldfields of Otago," by T. A. Kickard). 

Canton Lode. — The Canton lode lies about 600 yards to the west of the O.P.Q. 
At the present time the mine is not accessible, and as the outcrop of the lode is covered 
with alluvium and material excavated from the shaft it was impossible to make any 
observations. T. A. Rickard,* however, gives a fairly full description of it. .Judged by 
his accomit, the lode in its general nature is similar to the O.P.Q. Li other words, 
there is a relatively wide lode-formation of sheared, broken, and contorted country 
rock or mica-scliist. Within this broken zone, and particularly on the foot-wall, there 
are bodies of auriferous quartz. 

The Canton lode is not mentioned in Hutton and Ulrich's work on the geology 
of Otago published in 1875. The first reference to it is contained in " Reports of the 
]Mining Industries of New Zealand " (1888), where it is said that the Canton Claim 
had been taken up by Long and party. It was originally worked by Chinese, but 
abandoned. In 1896 the lode was again prospected by .several parties. It was again 
pegged out in 1908, and in the following year the mine was imwatered and good stone 
was fou]id. In 1912 the mine was worked by R. J. Cotton. The shaft was sunk 
to a depth of 180 ft., but working was restricted to the 75 ft. level. Mr. R. J. 
Cotton states that the lode was 4 ft. wide in places, and that the mullock of the 
lode-formation gave good assays for gold. Two exceedingly rich specimens were 
obtained of a total value of £120. Levels have been driven on the lode 100 ft. 
to the south and 60 ft. to the north of the shaft. The mine was worked by steam- 
power with an engine and machinery misuited for the purpose, which caused the 
cost of treatment to be very high. Assays of the mullock lying round the shaft 
gave a trace of gold only. The tailings at the battery gave an assay of £1 Is. 6d. 
per ton. The lode strikes 156°. 

Sandagger's Lode. — Half a mile north of the Canton lode, on the south-west side 
of the hill which separates the Waipori Flat from Mitchell's Flat, a small quartz 
vein has lately been discovered by Mr. F. Sandagger. This has a strike of 164°, 
with a dip of 62° to the east. The width of quartz is small, but there is a considerable 
tliickness of lode-formation or mullock. Scheelite is irregularly distributed in the 
quartz, which has an assay value of £1 Os. 4d. per ton. The small size of the quartz- 
body at present exposed has not encouraged development of the lode. 

Nuggety Gully Lode. — Li Nuggety Gully, about half a mile distant from Waipori 
Town.ship, a lode was formerly woiked with success, but no reference to the working 
of this lode can be found in the literature available to the author. The workings, 
however, still show on the surface, and it appears that they extended for a distance 

* Rickard, T. A. : Trans. Amer. Inst. Min. Eng., vol. xxi, 1893, p. 417. 



39 

of 600 ft. along a line bearing 146°. It is said locally that the widest part of the 
ore-body was 4 ft. and that the workings extended to the creek-level, and stopped 
at that point owing to the difficulty of coping with the water. The only quartz now . 
visible is on the north-west side of the gully, where the walls are well defined, but 
the quartz is only 6 in. thick, and on assay gives only a trace of gold. As judged 
by the extent of the earlier workings and from local information, the quartz appears 
to have been moderately rich. Nuggety Gully itself, as the name implies, yielded 
coarse detrital gold in considerable quantity during the earlier days of alluvial mining 
in the Waipori district. 

ABC Lode. — In Oharley's Gully, one mile north-west of Waipori Township, a 
small lode known as the ABC! has been worked to a considerable extent, but the date 
of the working cannot be stated. The lode strikes 156°, and dips almost vertically. 
It is said that a considerable amount of specimen gold was taken from it. 

Cemetery Lode. — Directly behind Waipori Township, in the small gully beyond the 
cemetery, there is a considerable quantity of quartz boulders, and with them a fair 
amount of rhodonite. The exact outcrop of the formation is now hidden by surface 
detritus. 

Bella Lode. — The Bella lode is situated on a branch of Long Gully, about five 
miles from the Waipori Township, and on the south side of the road leading' to the 
antimony-mine at an altitude of 1,800 ft. The lode strikes 90° and stands nearly 
vertical. It has a maximum thickness of 6 ft., but over the greater part of its 
extent is much less. The lode appears to have been worked by Stewart and Gare in 
1891, and was sold to Knight in 1895. In 1899 a crosscut was driven for a length 
of 400 ft. and exposed the lode varying from 2 ft. to 6 ft. in thickness, of an average 
value of i oz. per ton. In 1900 it was stated that the ore was rich but required 
chemical treatment, and the mine was shut down. The workings are not now accessible, 
but a portion of the reef was found still in position near the surface. This showed 
distinct walls without lode-formation or mullock. An assay of this stone gave a 
value of £3 18s. 2d. per ton. Finlayson* states that at a depth of 50 ft. the block 
of quartz rati over to one wall and wedged out, its place being taken by lode-forma- 
tion or mullock. The lode was found to contain some scheelite. 

Coxa Lode. — This lode is situated about four miles north of the Waipori Township, 
on the eastern slopes of the Lammerlaw valley, near the head of Battery Creek. 
It strikes 97° and is almost vertical, though in places there is a definite hade towards 
the north. There are good well-defined schist walls, but the lode when worked 
was found thin throughout, though there were two considerable expansions called locally 
the Maori and the Maud. As far as can be seen, the quartz is not more than 1 ft. 
wide. It has generally a comby structure, with small but well-formed crystals of 
quartz, some of which show trapezohedral faces. The country is schist, which .strikes 
176° with a dip of 6° to the east. 

In Co.v's lode good specimen gold was found, and a large quantity was obtained 
when it was first worked. It does not appear to have been tested before 1875, but in 
the Mining Reports for 1891 the mine is said to have been reopened, while in 1908 
further prospecting was undertaken, and the last work was done in 1910. The lode 
has been attacked at three levels, but the workings have not extended to any great 
depth, and it is said that quartz still shows imderfoot in the lowest level. Though 
the lode is of small size, it is probable that much gold can yet be obtained from it. 

* Finlayaon. A. M. : " The Geology of the Quartz Veins of the Otago Goldfields." Trans. N.Z. Inst., 
vol. xli, 1909, p. 75. 



40 

On the east bank of the Lammerlaw Creek a small vein has been found by 
Mr. F. Rogers. It strikes 90°, but is only Sin. wide. This may be a continuation 
of Cox's lode. 

Cosmopolitan and adjoining Lodes. — -The Cosmopolitan lode shows on both sides 
of Lammerlaw Creek about one mile distant from Cox's lode in a southerly direction, 
but no work of any magnitude has yet been done on it. The quartz, which is 
only Gin. to 9 in. wide, strikes 93°. It is said that a trial crushing of quartz from 
this vein gave a return of -J oz. per ton. Samples obtained from near the surface, 
however, proved to be very poor, as is shown by the following assay results : Clear 
quartz — Grold, none ; silver, trace. Smoky quartz — Gold, none ; silver, 5 dwt. 5 gr. 

Quite recently (March, 1917) wolfram has been discovered by Rogers and party 
in this vein. A sample sent to the Dominion Laboratory yielded 39 per cent, of 
tungstic oxide, and a selected piece analysed as high as 60 per cent, of WO3. 

Two other small lodes were visited near the Cosmopolitan. They arc situated 
on a spur 300 yards farther south, and strike 311° and 319° respectively. The quartz 
is very white, and not more than Gin. wide. None could be found in situ at the 
tinie of the visit. It is said that the value had been fomid to be 7 dwt. of gold 
per ton. 

Half a mile farther south large blocks of white quartz occur on the hillside. 
The lode from which these had been shed was not seen. 

Fulton's Lode and Neighbourhood. — Fulton's lode is situated on the south side 
of Stony Creek, six miles from Waipori. It strikes 268°, and hades to the north 
at an angle of 20° (equivalent to a dip of 70°). It has a maximum width of 3 ft., 
but does not maintain this for any distance. Only a small amomit of prospecting 
has yet been done on this lode, but it is known that the sides of the gully below it 
were remarkable for the rich allu^dal gold obtained in a coarse state. A sample taken 
from Fulton "s lode contained no gold and only a trace of silver. 

There is a large show of very white quartz along the ridge on the west side 
of Stony Creek above Fulton's Creek, and one mile below the Antimony lode. The 
lode strikes 321°, and has a flat dip of 15° to the south-west. It is 2ft. Gin. wide, 
and can be traced for nearly a mile. An assay showed that it contamed no gold 
or silver. 

Lodes on Lammerlaw Mountains. — Some work has been done on a small vein at the 
head of Fiddler's Creek, a small south branch of Deep Stream, at an altitude of 
2,600 ft. The outcrop of the vein strikes 92°. A large quantity of alluvial gold was 
obtained from the gully adjoining the outcrop, but a sample of quartz from the vein 
showed no gold and only a trace of silver. 

A thin vein strikes across Devil's Creek 300 yards above its jimction with Deep 
Stream. It strikes 82°, with a hade of 15° south. It runs parallel to the joints of 
the schist, which is almost horizontal in its lamination. Two small drives have 
been excavated, one on either side of Devil's Creek. A sample of quartz gave 
3 dwt. 6 gr. of gold and 4 dwt. of silver per ton. 

Another small lode is apparently parallel to the Devil's Creek vein, and is 200 yards 
farther north. It shows no good outcrop, but is regarded as the source of a great 
deal of the allu\aal gold found in the gully below it. 

On the north side of Deep Stream, 300 yards above its jiuiction with Devil's 
Creek, some scheelite was formerly obtained from a lode which strikes 83°. The 
outcrop is now hidden by peat and detritus. 

A good deal of work was done by Harry Anderson Bootleman on a lode situated 
on the north side of Deep Stream, half a mile above its junction with Devil's Creek. 



Bxill.N? 19 




P G.MORGAN 

DIRECTOR. 




QUARTZ LODES 
I. Nugget^ Gully 

Z. ABC 

3. Cosmopolitan 

4 Cox's 

5. Bella 

G Fiddlers 

7. Buck ■ 

8. Fulton's 

9 Canton 
10. O.P.Q. 

II Devili Ck. 

12. Antimony Lode. 
15 Boatmans 

5CHEEUTE BEARING LODES 



13 Burtenshatv's 
14. Deep Stream 



— MAP OF — 

WAIPORI DISTRICT 

Showin g Lodes 



- Scale of Chains - 



I l-l >-l ^^ 



^Z 



:£ 



Kilometif 



<?.£:// 



41 

This lode was developed by means of a large drift, and a three-stamp battery was 
erected to treat the quartz. Work was continued for four years, but the results 
are not known. The drive is now filled with water. 

Canada and Ocean View Lodes. — Hutton and Ulrich* give a full description of 
this lode, which was being worked in 1875. It is situated on the eastern side of 
the south branch of the Tokomairiro River. The enclosing rock is less schistose than in 
the rest of the area where lodes occui-. The country rock strikes 133°, with a dip of 15° 
to the north-east. Locally the lode is as much as 4 ft. thick, or, according to Ulrich, 
even 7 ft. The quartz varies much ; in some places it is white and hungry-looking, 
but at others darker and more mineralized. There are two distinct veins, 120 yards 
apart, and quite parallel. The southern one is the Canada reef or lode, the northern 
Ocean View or Table Hill lode. Both veins strike 106°, with a hade of 19° (or dip 
of 71°) to the north. 

Hutton and Ulrich record the fact that a portion of the Canada reef had a value 
of 5 oz. of gold per ton, but the value generally lay between 2 dwt. and 6 dwt. per 
ton. The most extensive workings took place in, 1874-77, and during these years 
9,110 tons of quartz were treated for a return of 2,097 oz. of gold. The workings 
extended to 150 ft. only from the surface. Li 1895 a low-level adit was made 40 ft. 
above the bed of the Tokomairiro River. This was driven parallel to the lodes for a 
distance of 400 ft. It was intended to extend the adit for another 300 ft. before 
crosscutting to the lode. If this was carried out it appears to have been unsuc- 
cessful, for no mention is made of it in the Mines Report of the following year. 

In 1899 a battery had been erected on the bank of the river, and 200 tons of 
quartz were crushed for a return of 5 dwt. per ton. In 1905 the lode was worked 
at a spot one mile to the east of the former workings, and ore worth 1 oz. to 3 oz. 
per ton was obtained, but in 1907 this shoot of stone was exhausted. Li 1908 the 
mine was sold to a new company, and the shaft was extended to 120 ft., at which 
depth the block of stone was fomid to be much narrower. 

At the present time it is not possible to see much of the mine. There are 
a large number of small shafts along the line of reef, but these have fallen in and 
the workings are not accessible. A specimen of quartz was obtained from a small 
block showing in an adit near the top of the hill facing the Tokomairiro River. This 
gave an assay value of 2 dwt. 14 gr. per ton. 

GabrieVs Gully Lode. — This lode occurs on the western side of the ridge or hill 
(Clarke's Hill) between Gabriel's Gidly and Wetherstones, and on it high hopes were 
originally centred, for it was considered a probability that it was one of the sources of 
the gold which has rendered the Bluespur " cement " so famous. The lode, however, 
proved to be small, with isolated blocks of stone, none of which had a high value. An 
account of the lode will be found in Hutton and Ulrich 's " Geology of Otago," p. 195. 
According to a report by Mr. Vincent Pyke,| Warden, cm.shing began in November, 1872, 
and up to the 31st March, 1873, 1,500 tons of ore had been treated for a return of 470 oz. 
of gold. In 1874 Mr. E. H. Carew,J Mr Pyke's successor, states that the Gabriel's Gully 
Quartz-mining Company had crushed 4,000 tons of ore for a total return of £4,025. In 
1875 the company collapsed, but in 1878 and again in 1882 the Warden reports that 
Clarke's Hill was being reprospected. Though in 1879 a new reef was reported as having 
been discovered between Bluespur and Wetherstones, no tangible result followed these 
operations. 

* Hutton, F. W., and Ulrich, G. H. F. : " Geology of Otago," p. 193. Dunedin, 187.5. 
•j- Wardens' Reports in " Report on the Goldfields of New Zealand," H.-7, 1873, p. 29. 
j Wardens' Reports in " Report on the Goldfields of New Zealand," H.-9, 1874, p. 25. 



42 

Gray's Gidlif. — Gold has recently been discovered near the head of Gray's Gully, a 
small affluent of the upper part of the Tuapeka River on its left side. Coarse alluvial 
gold was obtained in this gully, and on the point of a small spur near its head specimen 
gold was found. Excavation showed that the spur consisted of crumpled schist, and 
from the quartz lenticles of the rock good specimens were obtained, as well as prospects 
from the powdered quartz. In places the rock between the quartz lenticles showed 
colours of gold. Here there appears to be conclusive evidence of the occurrence of gold 
in some quantity in the schist, especially in the quartz lenticles. It is true that the 
schist is much crumpled, and for that reason the deposit might be classed by some 
observers as a lode-formation. No body of quartz more than the usual schist lenticles, 
Sin. or 4 in. across, is to be seen, and blocks of quartz were quite absent from the alluvial 
sands and gravel of the stream when hydraulic sluicing was being conducted. 

Simpson's and Burnt Creek Veins. — Simpson's lode and Burnt Creek lode, three 
miles north of Havelock, are small bodies of quartz showing on the surface fairly 
distinctly. Some prospecting has been done along the line of reef, but nothing of any 
importance has been disclosed. A small quantity of quartz from the Burnt Creek vein 
was crushed in 1899, but the yield was at the rate of only 2 dwt. per ton. 

Origin of the Gold. 

The question whether the gold found in the Tuapeka Series was originally a com- 
ponent substance of the sediments or whether it was introduced subsequentl)' to their 
deposition along zones of crush and fracture by auriferous solutions is an extremely 
difficult problem to solve. Various points in regard to the occurrence and distribution of 
the gold require consideration in this connection. These may be summarized as follows : — 

1. With the exception of the Canada lodes and cement-deposits the gold is restricted 
to the region where the rocks are completely metamorphic. 

2. Li this district of metamorphic rocks gold occurred not uncommonly in the alluvial 
deposits of even the smallest streams, and this gold was but slightly water-worn. 

3. No alluvial gold was found in the stream-valleys round the Canada lodes, and 
but little near the O.P.Q. lode. 

4. Alluvial gold, rough and not water-worn, was found in a very large number of 
small stream-valleys where no lodes have been found in the watershed. 

5. Rough and heavy gold was found in R. J. Cotton's claim at the foot of the 
spur between the Nardoo and Lammerlaw streams. This was very slightly water-worn, 
and no lode can be found on the spur. 

(i. Taking the district as a whole, prospecting has been complete and thorough, but 
this has revealed relatively few lodes, and these have generally been small and poor. 

7. At Grays Gully gold actually occurs m schist rock where there is no body of 
quartz other than the ordinary lenticles of this mineral in the schist. 

8. A small speck of gold from the Bluespur alluvial field clearly shows a small 
portion of schist matrix associated with the gold. 

9. The flaky character of the gold suggests its formation in a rock that has been 
submitted to recrystallization under pressure, such as a schist. 

10. Careful assays of quartz lenticles are said by Professor D. B. Waters to reveal 
traces of gold in nearly every case. 

These facts appear to justify the conclusions that — 

{a.) Mere auriferous lodes have by themselves not been responsible for any 

important amount of alluvial gold in this district. 
(6.) Alluvial gold may be found iji localities where there are no lodes. 
(r..) Gold actually occurs in the schist. 



43 

It is further suggested that the gold was an original constituent of the greywacke, 
and that it has been subject to recrystallization in the same manner as the other 
constituents of the schists. On the other hand, there is no doubt that some of the 
alluvial deposits are much richer near auriferous lodes than elsewhere, and that large 
gold-specimens have in many cases been certainly derived from quartz veins. 

Those geologists who have thought that the gold has not been derived from 
detrital grain? in the greywacke have generally supposed that it has originated from 
a subjacent igneous magma. Thus Finlayson* states, " We must conceive that the 
vein-fissures when formed gave access to thermal waters charged with precious metals 
which rose from a magma beneath, wherein rock-dif!erentiation and ore-segregation 
had taken place.'' Of the existence of such a magma we have no independent evidence. 
There are no known acid dykes, plutonics or volcanics, in the greater part of the 
auriferous region of Otago. It is true that there is a large occui-rence of basic- 
alkaline volcanic rocks farther eastward, near Dunedin and the line of coast generally. 
There is also a large mass of basic volcanics some thirty miles north, extending 
nearly continuously from south of Hyde to north of Macrae's. In the neighbourhood 
of these igneous rocks, however, the schists are not more auriferous than elsewhere. 
A further objection to the derivation of the gold from a subjacent igneous magma is 
to be found in the general poverty of the lodes in any but the more superficial 
portions, where they are often quite rich. Though this may possibly be ascribed to 
secondary enrichment, the poverty of the reefs in sulphides must be borne in mind. 

Li conclusion it may be stated that the observations made and facts cited strongly 
support the belief that the gold was an original constituent of the greywacke. 

Antimony Lode, Lammerlaw Mountains. 

This lode occurs along the bed of Stony Creek, nine iniles fiom Waipori Township. 
The lode appears to have been taken np in 1880, when 2^ tons were sent to London. 
Work was commenced again in 1888 and in 1894. There were two shafts, 400 yards 
apart, in the bed of Stony Creek. The lode-formatioti is 4 ft. to 5 ft. wide, but carries 
only Lift, of .stibnite-bearing material. The strike is 109°, with a hade of 30° south. 
The country schist is horizontal at the lower shaft, and strikes 135° at the upper 
shaft, with a dip of 4.5° south-west. The ore is stibnite, of which good samples can be 
obtained. It is, however, associated v\ith much quartz, and along the strike a change from 
stibnite to quartz may occur in a few inches. The lode is still showing at the west end 
in an open-cut, but here there is very little antimony-ore. In places the stibnite is 
encrusted with the yellow oxide, cervantite. The workmgs are not now accessible, 
and it is not possible to say what prospect there is of obtaining further quantities 
of ore. 

During the mining operations a large mass of scheelite was discovered in the 
middle of the lode. It is said to have been soft, and to have been easily extracted 
with a shovel. Mr. W. Russell informed me that 5 tons were extracted, and subse- 
quently a further 2 tons were washed from the dump-heap. Finlayson f states that 
gypsum was associated with the scheelite. He regards this as secondary, and due 
to a reaction between the sulphur of the stibnite and the lime of the scheelite. In 
1907 the mine was again unwatered, but no further work was done. 

Stibnite occurs in schists at Alexandra and at Endeavour Inlet. The author 
is not able to offer any satisfactory suggestion as to the origin of the ore. 

♦Finlayson, A. M. : Trans. N.Z. Insb., vol. xli, 1908, p. &4. t ^bid., p. 76. 



44 

Waitahuna Copper Lode. 

This lode was briefly described by Hutton and Ulrich.* It is situated on the east 
side of Reedy Creek^ — -that is, the south branch of the Waitahuna River, nine miles 
from Havelock. The country is a mica-schist with a strike of 174° and a dip of 
16° to the south-west. The lode is now exposed only as a much-oxidized gossan 
about 4 ft. thick, dipping with the coimtry. In 1882 a shaft was sunk near the 
bank of the stream to a depth of 70 ft. The spoil from this shaft shows good speci- 
mens of yellow sulphide ore, which contains as much as 24 per cent, of copper, with 
13 dwt. of .silver and 9-4 gr. of gold per ton. The shaft is now full of water, and 
it was not possible to see che lode except at one point on the surface. The ore is 
a fine-grained mixture of pyrite and chalcopyrite, and in the samples obtained is free 
from quartz. Ulrich says that the vein is 1 ft. thick, but local statements based 
on work done subsequently give it a much greater thickness. The lode is less than 
a mile distant from the Waitahuna- Waipori Road. The present condition of the 
lode does not enable an observer to give any opinion as to the amount of ore that 
could be obtained. A little work was done on the mine by Eaton in 1907, but 
no result of any moment was accomplished. 

Origin of the Copper. — -The deposit on the Waitahuna River appears to be the 
only occurrence of copper-ore in this district. No facts could be discovered in the 
immediate neighbourhood of the deposit that seemed of any importance in indicating 
its origin. The only suggestion that can be made is that, since there are numerous 
basic and alkaline -basic volcanic rocks at no great distance to the east, the formation 
of the copper-ore may be associated with the rock-differentiation which took place 
in the magma from which these volcanic rocks were derived. The occurrence of 
copper is localized and comparatively close to the volcanic rock, though it may be 
hazardous to suggest any relation between the two. 

Cinnabar. 

This mineral has been fomid constantly in the alluvial-gold workings between 
Waipori and the Waitahuna Heights. The fragments of cinnabar were always more 
numerous and larger near the latter locality. In 1899 a vein was discovered half 
a mile north-east of the highest point of the Waitahuna Heights, at the head of a 
small gully trending north-east. A drift was put in along the line of the vein, wliich 
showed that it varied greatly, yielding fine bunches of ore occasionally. In 1901 
it was decided to drive an adit from the bottom of another gully 400 yards to the 
north-east. This was driven for a distance of 200 ft., not (juite far enough to intersect 
the lode. The cinnabar occurs in a broken band of schist lode-formation about 4 ft. 
wide, but is found in small streaks and larger bunches on the hanging-wall only. 
The lode-formation strikes 94°, and hades 28° to the eastward. The enclosing rock is 
partly metamorphic sandstone, often crushed. It has a strike of 50°, with a dip 
of 12° to the south-east. The small amount of cinnabar at present showing, and the 
fact that the low-level drift does not intersect the lode, prevent the formation of 
any definite opinion about its value. The cinnabar, however, is of remarkably good 
quality. 

Origin of the Cinnabar. — Although the lode at the top of the Waitahuna Heights 
is the only place where a cinnabar-deposit has been found in situ, there is a wide occur- 
rence of the mineral in the alluvial deposits of the Waipori district. Thus the Golden 
Padlock Claim and elsewhere on the Pioneer Creek, the Nardoo Creek, Lammerlaw 
Creek, and Deep Stream are all localities where this mineral occurs. Here again 

* Hutton, F. W., and Ulrich, G. H. F. : " Geology of Otago," 1875, p. 184. 



45 

the localities are relatively close to the eastern belt of basic volcanic rocks, and it 
is possible that the genesis ot the cinnabar is related to the igneous intrusion 
that was the cause of the volcanic eruptions. This ore also occurs in localities 
relatively close to the volcanic outcrops. 

Scheelite. 

This mineral was found by the early alluvial-gold diggers, who obtained it in 
the concentrates when washing for gold. It was thus found to have a general occur- 
rence over the Waipori goldfield. Of late years, since the mineral has become of 
considerable value, search has been made for regular deposits. The first of these to 
be worked was situated on the right bank of the Lammerlaw Creek, about one mile 
north-west from Waipori. The strike of this lode is 56°, and the dip 38° to the 
south-east, parallel to the schist. Some 12 tons of scheelite were obtained, and the 
lode was followed to a depth of 20 ft., where it completely pinched out. Subsequently 
F. Sandagger put in a low-level adit to inter-sect it ; but where the scheelite should 
have been cut there was merely a narrow vein of pug, showing no scheehte, but a 
little gold. 

In November, 1915, Burtenshaw found a snjall vein carr}^ing scheelite near the 
upper end of the Lammerlaw deep lead, about half a mile distant from Waipori. 
The scheelite was associated with much quartz. The vein has a strike of 75°, and 
a dip of 44° to the south-east, is 6 in. thick at the widest point, and can be traced 
for 30 yards, though clearly visible for 10 yards only. This vein also is parallel to 
the foUation of the schist. It has been traced to a depth of 10 ft. 

On the south side of the O.P.Q. lode, along the hne of strike of the Canton lode, 
there is an auriferous-reef formation about 3 ft. wide, with a thin vein of scheehte 
on the hanging-wall. The scheehte, however, gave out when followed along the 
strike. At this place the lode-formation strikes 164°, and dips at 62° to the east- 
ward (?). 

Another occurrence of scheehte is in R. J. Cotton's claim in the Nardoo Creek. 
The outcrop is now covered by the gravels of the creek-floor. Some of the boulders 
thrown out when the outcrop was exposed during sluicing operations gave an assay 
of 15-5 per cent, of tungstic acid. 

A small quartz vein on the right side of the Lammerlaw valley, about a mile 
and a half from Waipori, carries scheehte, but all the ore exposed by prospecting 
operations was of low grade. 

Scheehte has also been obtained from the .summit of the Lammerlaw Mountaiiis 
on the left bank of the Deep Stream, 400 yai'ds above its junction with Devil's Creek. 
The workings are now filled in, and no idea of the extent of the deposit can be obtained. 

A further occurrence of scheehte was found by W. Ru.ssell in the bed of a small 
tributary of Deep Creek, well up the slopes of the Lammerlaw Mountains. There is a 
quartz lode 1 ft. wide which gives good prospects of scheehte, and this mineral has 
also been obtained in some quantity from alluvial ground close at hand. The scheelite 
lode strikes 115°, and hades 55° to the southward. The foliation of the schist near 
at hand is almo-st horizontal. 

Origin of the Scheelite.- — It is well known that tungsten minerals are originally 
formed during certain phases of the consolidation of granitic magmas. This is the 
case in Tasmania,''' New South Walesf and Queensland, and in England. J In the 

• Hills, Loftus : Tas. Geol. Sur. Min. Resources, 1916, pp. 4, 5. No. 1, Tungsten and Molybdenum. 
■f Came, J. E. : " The Tungsten -mining Industry of New South Wales," 1911, pp. 30-49. 
j Deevey, H., et alii : .Special Report on the Min. Res. of Grt. Brit., 1915, pp. 1, 3. Vol. 1, Tungsten 
and Manganese Ores. 



46 

greater number cf these localities, however, the tungsten-ore (wolfram) occurs without 
scheehte, though in the scheelite-mines themselves in New South Wales it appears 
to be a general fact that the scheehte occurs in quartz veins which traverse granite 
countr}'. 

California is a large producer of scheehte, and here again the mineral occurs in 
veins in association with quartz in a countiy rock of granite. 

The deposition of the tungsten-ores is always believed to be associated with the 
pneuniatolytic phase of the consolidation of the granite. As the cr}'stallization of 
the normal minerals of the granite proceeds, the tungsten compounds become con- 
centrated in the residue, which contains a large amount of water, as they have con- 
siderable solubility in this residue. In the final stages of consolidation this residue 
is forced into cre\'ices that have formed in the portion of the granite that has pre- 
viously become solid. In these crevices the acidic residue solidifies as veins. This 
pneumatolysis is believed to be an active process in all plutonic magpias. A difficulty 
is at once presented in any attempt to ascribe the origin of the Otago deposits of 
scheehte to any such action, for there is no granitic outcrop anywhere within the 
schist area or in the vicinity. In addition, no dyke rocks of an acid nature 
have been found penetrating the schists, nor are any acidic volcanic rocks known 
to occur within the Otago Province. It is, however, well known that a dyke of 
feldspar-porphyrite traverses the greywackes at Nugget Point. Quite recently a large 
mass of plutonic rock has been found west of Gore, but this rock is not younger 
than the greyWackes. There is thus no independent geological evidence whatever in 
favour of the association of the scheelite-deposits of Otago with a granite magma. 

The association of a bunch of scheehte with the stibnite in the Stony Creek vein 
does not appear to have any special significance so far as derivation from an igneous 
magma is concerned, for stibnite appears to be found in a great variety of country 
rock.* 

It is also significant that the scheehte occurrences that have been described run 
parallel to the fohation of the schist, and, apart from the presence of scheehte, have 
no characters that distinguish them from the ordinary quartz lenticles of the schist 
rock. According to Finlayson| the scheehte occurrences at Macrae's present similar 
features, though they are of much larger size. Notwithstanding these facts, Finlayson 
concludes, " It is evident that the tungstic acid of the scheehte has ascended through 
the schists by way of the lode-fissures, and the fact that tungsten is a characteristic 
element in ore-deposits associated with granitic rocks leads to the inference that the 
magmas beneath were largely granitic in character." This statement of Finlayson's has 
apparently been responsible for the following sentence in a recent text-book: "The 
pneuniatolytic origin of some gold veins is again proved by the occurrence of the 
metal with wolfram and other minerals. ... It is found associated . . . with 
wolfram and scheehte at Otago (New Zealand) associated with granite. The veins 
are of the true cassiterite type, but are characterized by an unusual amount of gold. "J 
In nearly every place where the scheehte has been found the veins have been thin, 
and pass laterally into quartz lenticles of the schist, in which there is practically no 
scheehte. The quartz lenticles themselves soon lose their individuahty, and cannot 
be followed for any great distance horizontally or vertically. This fact again makes 
it extremely unhkely that these veins can be associated with any granitic magma, 
for in such a case it would be reasonable to expect that the veins would live as they 

* Came, J. E. : " Antimony Mining and Distribution in New South Wales." Min. Res. No. 16, p 48, 
" The Geological Occurrence of Antimony-ores." 

t Finlayson, A. M. : " The Scheelite of Otago." Trans. N.Z. Inst., vol. xl, 1908, pp. 119-120. 
j Thomas and Macalister : " The Geology of Ore-deposits." London, 1909, p. 108. 



47 

were followed downwards. The lensoid nature of the scheelite-deposits is especially 
clear in connection with the occurrence on the spur between the Nardoo and Laninier- 
law creeks. Here a considerable quantity of scheelite was obtained from an outcrop. 
This was followed laterally and along the dip, but it completely disappeared in both 
directions after being traced for some 40 yards laterally and 30 ft. along the dip. 
The quartz and scheelite lens decreased gradually in width, and there can be no 
suggestion of faulting. Had the ore been derived from a granitic magma it does not 
appear possible that such a type of deposit could have been formed. 

While it is true that there is no independent evidence whatever of the presence 
of any subjacent granitic magma, attention may be drawn to the fact already indicated 
that the greywackes from which the schist was derived are themselves composed mainly 
of granitic detritus, and hence may conceivably contain some small proportion of 
tungsten minerals. Thus it is a noticeable fact that in Otago scheelite-deposits occur 
only in those areas where the fohated structure of the schist is complete. It is now 
well known that the foliated structure of a rock implies entire recrystallization . In 
other words, the original minerals of the greywackes, including such of them as con- 
tained compounds of tungsten, have been dissolved little by little, and each small 
quantity that was dissolved has been deposited, and has thus allowed of the solution 
of further material. In this way all the material of the rock has been in time dissolved and 
deposited, and the rock as a whole has been recr}''stallized. Such a process is clearly 
seen to be associated with the segregation of much of the silica into lenticles of quartz, 
and similar segregation of other minerals is frequent. It is not unreasonable to ascribe 
the formation of the scheelite-bearing lenticles to a similar action. The complete 
recrystallization which has given rise to the schist may reasonably be regarded as 
affording an opportunity for the recrj'stallization and segregation of the tungsten-ore. 



48 



CHAPTER VI. 



WAITAHUNA SERIES. 



Page 

Subdivision of Series . . . . . . 48 

(1.) Auriferous Conglomerate or "Ce- 
ment " . . . . . . 48 

Historical and General Account . . 48 

Bluespur . . . . . . 50 

Wetherstones . . . . . . 53 

Forsyth . . . . . . 54 

Waitahuna Gully . . . . 55 

Adams Flat . . . . . . 56 

Glenore . . . . . . 57 

The Taieri "Moraine "' . . . . 57 

Origin of the " Cement " . . 58 

Palaeontology and Age of the 
"Cement" .. .. ..58 



Page 



(1.) Auriferous Conglomerate or " Ce 
ment " — continued. 
Economic Geology of the " Ce- 
ment " . . . . . . 59 

(2.) Quartz-grits . . . . . . 60 

Distribution . . . . . . 60 

Relation of Quartz-grits to Cements 61 
Age of Quartz-grits . . . . 62 

Economic Geology of the Quartz- 
grits . . 63 
(3.) Volcanic Rocks of the Waitahuna 

Series . . . . . . 63 

Conditions of Deposition of Waitahuna 
Series . . . . . . . . 64 



Subdivision of Series. 
The Waitahuna Series, so called from its typical development in the Waitahuna valley, 
includes all those rocks in the Tuapeka district that are younger than the Tuapeka 
Series, Quaternary deposits excepted. It may be subdivided into — 

(1.) Conglomerates — ^the so-called auriferous cement. 

(2.) Quartz sands and gravels — the so-called coal-grits or quartz-grits. 

(3.) Volcanic rocks. 



(1.) Auriferous Conglomerate or "Cement." 
Historical and General Account. 

The gold-bearing conglomerates have their best-known occurrence at the Bluespur, 
for in that place they have been the source of the large quantities of gold -which 
have been obtained from the neighbourhood of Lawrence. There are, however, much 
larger areas of the " cement " in the Tuapeka district. The localities at which it 
is known to occur are Wetherstones, Waitahuna Gully, Forsjrth, Glenore, and Adams 
Flat. At the Bluespur the area over which the rocks occur measures nearly a mile 
in a north-west - south-east direction by a quarter of a mile at right angles to that 
line. At Wetherstones the conglomerate area measures two miles and a half from 
north to south, and is nearly a mile wide at its broadest portion. At Waitahuna 
Gully it measures a mile from north-east to south-west, and three-quarters of a mile 
at right angles to this. The Forsyth area is one mile and a half long, and only 
half a mile across in its widest part. At Adams Flat the conglomerate area is certainly 
a mile long from north-east to south-west, and half a mile wide. At Glenore the area 
is probably small, and is so covered by gravel that its actual extent cannot be gauged. 
The conglomerate here outcrops in a river-flat, and for the most part has been revealed 
only by dredging and other gold-mining operations. 

At the Bluespur the conglomerate originally formed a ridge which separated Gabriel's 
Gully from Munro's GuJly. The ridge apparently rose to a height of about 300 ft. 
ajjove the floor of the gully on either side. At Wetherstones the outcrop extends 
over low-lying groimd, which rises to about 150 ft. on the surrounding hillsides. A 
similar arrangement is found at Forsyth, where, however, the level is 300 ft. higher 
than at Wetherstones. At Waitahuna, again, the conglomerate area rises on the spurs 
which boimd the valley. At Adams Flat the formation is not found high up on the 
hillsides. At Glenore the conglomerate is restricted to the floor of the valley. In all 



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49 

cases except at the Bluespur the area is low compared with the surrounding country ; 
and even at the Bluespur the conglomerate occurred in a dip or saddle in the con- 
tinuous spur which separates two stream-valleys of moderate size. 

Sluicing operations have largely revealed the structure of the areas where the 
conglomerates are found. An observer at the present day thus has a very decided 
advantage over those who have pre\aously examined the district. It is now very 
clearly seen at the Bluespur, Wetherstones, and Waitahuna Gully that the conglomerate 
area is bounded by a normal fault of considerable downthrow on the western side. 
A similar .structure is quite distinct in a railway-cutting and adjoining road at Forsyth. 
There is considerable evidence of it at Adams Flat, and at least a probability at Glenore, 
judging by the physiography of the surrounding land, for here high country formed of 
rocks of the Tuapeka Series occurs to the north-east of the flat, where the con- 
glomerate has been fomid. Ajialogy also lends probability to the .suggestion in the 
last case. 

It will at once be noticed that these conglomerate areas, but particularly Bluespur, 
Wetherstones, Forsyth, and Waitahuna Gully, are arranged in a most definite north- 
west to south-east line. This also is nearly the strike of the fault-plane in every 
instance. The actual directions of the fault-planes and their dips are given in the 
following list : — 

Bluespur.. .. .. .. .. lir-HS" 26° S.W. 

Wetherstones . . . . . . . . 109° 30' 26° S.W. 

Forsyth . . . . . . 172° 31° W. 

Waitahuna Gully . . .. .. 148° 167° 36° S.W. 

These facts suggest that all the areas of conglomerate occur along a single fault-line, 
which changes its strike slightly from point to point. This idea is not supported by 
field evidence, as hills of schist or altered greywacke separate each of these areas from 
those near it, and on these hills no special evidence of faulting can be seen. Evidence 
based on rock structure or nature would be hard to obtain because of the covering 
of clay and of vegetation, and also because of the general similarity of the rocks 
and the absence of recognizable petrological series. The physiographical features, 
however, do not suggest that the faults are continuous. At the Bluespur, Waitahuna, 
and Forsyth the bed-rock of schist dips towards the fault-plane on the downthrow 
side. Thus the faulting has produced relatively small basins, bounded on the western 
side by the sloping surface of the bed-rock and on the eastern by the fault-plane 
itself. Sluicing operations have now so far removed the auriferous conglomerate 
as to disclose the structure of the basins even to a casual observer. At the Bluespur 
the fault-plane is now exposed for a distance of half a mile, while down the slope 
of the disclosed fault-plane the measurement is 620 ft. At Wetherstones the fault- 
plane is interrupted by a thrust-movement with a strike of 155°, and a length of 
80 yards only is exposed. At Waitahuna Gully the fault-plane is exposed for a length 
of 650 yards, and for a depth, as mea.sured down the sloping face, of 150 ft. At 
Forsyth it has not yet been exposed by sluicing, but appears to extend for the 
whole length of the conglomerate area — that is, one mile and a half. At Adams Flat 
and at j^Glenore the existence of a similar fault-plane is a matter of inference and 
analog)' only. 

At the time of Mutton's visit in 1875 it appears that the Bluespur was the only 
deposit so far worked as to expose the fault-plane. The smooth flat surface of the 
plane gave Button* the mistaken impression that the Bluespur basin was an old glacial 

* Hutton, F. W. : " Geology of Otago," p. 93. Dunedin, 1875. 
4 — Tuapeka. 



60 

valley, and that the smoothness of the fault -plane was a result of glacial erosion. 
Glacial erosion was supposed to have formed a rock basin into which a river after- 
wards transported the auriferous gravels. The idea that the deposits of " cement " 
filled basins eroded by glaciers appears to have been adopted by Cox,* for he refers 
to glaciers transporting the materials of the " cement " to the basins in which they 
now occur. 

The same explanation was also adopted by Rickard,t who published a paper on 
this goldfield in 1892. The essential parts of this have been quoted in the " Goldfields 
and Mining Report of New Zealand," 1893, pp. 109-111, and in McKay's " Report 
on the Older Auriferous Drifts of Central Otago " (New Zealand Mines Report, 1894 ; 
second edition, 1897, pp. 5-7 ; also pp. 93, 94). Although Rickard recognizes the fact 
that the basin is bounded by a fault on the north-east side, he still follows Hutton 
in ascribing great importance to glacial erosion in forming the basin, as well as to the 
deposition of glacial detritus in it afterwards. 

McKay:]: appears to be the first geologist who opposed this explanation, which had 
been so generally adopted. He says with emphasis, '' Nowhere can the evidence of 
ice-action be seen at the Blaespur, Wetherstones, or at Waitahima, and there is no 
need for such an hypothesis. The so-called basin has not been scooped out, and 
the material filling it, though angular, being locally derived in the lower part, is not 
of morainic origin." Park§ referred to the Bluespur deposit in 1908. He states 
that the conglomerates are of glacial origin and of Pleistocene age. This opinion is 
repeated in " The Geology of New Zealand," 1910, pp. 191-94. He further represents 
the rock-movement as taking place along a reversed fault. 

Bluespur. 

At the Bluespur the basin containing the " cement " is, as stated by McKay, 
due to the movement of 600 ft. down a fault-plane, while on the downthrow side the 
siirface of schist rock slopes at an angle of 15° towards the fault-plane. The gutter 
thus formed reaches its lowest point about 200 yards from Gabriel's Gully side, and 
from that point rises to both the Mimro's Gully side to the north-west and the Gabriel's 
Gully side to the south-east. The bottom of the gutter is not accessible or visible 
at the present time, and reliance has to be placed on the statements of miners who 
were formerly employed in excavating the rich bottom of the conglomerate on the 
downthrow side of the fault. A portion of the gutter is shown in a photograph pub- 
lished in the Mines Report, 1911, opposite p. 48. In addition to the slope of the gutter 
towards both ends of the deposit, some irregularities occurred. The big " jump-up," 
distant some 300 yards from Gabriel's Gully end, is now partly exposed owing to 
the removal of much of the " cement " by sluicing. It is suggested by McKay|| that 
this jump-up was the result of cross-faulting. If so, such faulting must have taken 
place previous to the great structural fault bounding the basin, as no sign of any 
jump-up is to be seen on the face of the fault. 

The structure of this basin is therefore as follows : A large fault bounds it on the 
north-east side, dipping at an angle of 25°. On the south-west side the downthrown 
Bchist slopes to meet the fault-plane at 16°. The gutter along which these two surfaces 



* Cox, H. S. : " The Tuapeka Cements." Rep. of Geol. Explor. during 1878-79, No. 12, 1879, pp. 51, 52. 

t Rickard, T. A. : Trans. Amer. Inst. Min. Eng., vol. xxi, 1893, pp. 438 et seq. 

i McKay, A. : " Older Auriferous Drifts of Central Otago," 2nd ed., 1897, p. 94. 

§ Park, J. : N.Z. Geol. Surv. Bull. No. 5, frontispiece and p. 10. 

II McKay, A. : " Older Auriferous Drifts of Central Otago," 2nd ed., 1897, p. 9. 



51 

meet slopes upwards about 5° witli some irregularity to Munro's Gully, and at about 
the same angle in the south-east direction to Gabriel's Gully. Either this slope in the 
gutter is due to the intensity of the fault-movement decreasing both north-west 
and south-east, or else the schist surface on the downthrow side was worn into a 
broad channel from south-west to north-east before the deposition of the conglomerate 
and the faulting took place. The former suggestion is supported by the fact that 
the great fault-plane cannot be traced in the schist on the south-east side of Gabriel's 
Gully or on the north-west side of Munro's Gully, and the auriferous conglomerate 
is entirely absent in both of these places. It is suggested by McKay* that these facts 




Cement - old border ^ ^ "n ^ 



PLAN OF 
BLUESPUR WORKINGS 



Scale o( CHams 



might be explained by the presence of cross-faults along the floor of Gabriel's Gully 
and of Munro's Gully, but no evidence of the existence of such faults could be found. 
The material of which the Bluespur conglomerate is formed has been accurately 
described by several observers. McKay's| description seems the most comprehensive. The 
conglomerate is well stratified, and dips with the schist surface on which it rests 16° to 
the north-east. The material is mostly a moderately coarse gravel, with boulders very 
seldom reaching 18 in. in diameter. There are some fine sandy and even shaly 
laminae, and some of the latter contain lignitic matter with leaf-impressions. A 
portion of the trunk of a tree some 20 ft. long and more than 12 in. in diameter was 



* McKay, A. : " Older Auriferous Drifts of Central Otago," 2nd ed., 1897, p. 9. 

t McKay, A., he. cit., pp. 8, 9. 

4* — Tuapeka. 



62 

obtained from this portion. It is now in the possession of H. L. Darton, of Lawrence. 
The boulders consist mainly of schist, such as that now found in the northern portions 
of the district near Waipori. There are, however, a considerable number of dark- 
purple quartzose boulders which contain much magnetite. As these boulders are 
extremely hard, and have a smooth unweathered surface, many of them were carefully 
examined to see whether any signs of glacial striations could be detected, but nothing 
of the kind could be found on them. Hutton stated that these boulders must have 
come from the Tapanui Mountains, and made use of this behef in supporting his 
theory of a glacial origin for the conglomerates. McKay, however, rightly points out 
that the boulders have really been derived from the crystalline schistose series of 
rocks lying to the north and north-east. There are also boulders of greywacke very 
shghtly altered. These must have come from some twenty miles to the south-west. 
The examination of the boulders shows that all the material has a comparatively local 
origin, and (apart from the fact that the deposit itself rests on metamorphic rocks) it 
also proves that the erosion of the surface of the district had, before the deposition of 
the conglomerates, already proceeded so far as to expose the schistose rock-types, which 
presumably had been deeply buried at the time of their change from greywacke to schist. 

The boulders and pebbles of the conglomerate are firmly united together by fine- 
grained detritus. This fine-grained material consists of the same matter as the boulders, 
and, like them, gives no suggestion of glacial origin or deposition. Slight chemical changes 
within this fine-grained matter have caused it to set relatively hard, and thus justify 
the application of the miners' term " cement " to the whole deposit. The upper portion 
of the " cement " has been subjected to the oxidizing action of percolating rain-water, and 
the bluish colour of the main portion, which has given rise to the name Bluespur. has, 
for at least the upper 10 ft., been changed to a dark-orange or red colour owing to the 
oxidation of the compounds of iron. The contrast between the colours of the blue 
" cement " and the red " cement " was for a long time supposed by the early miners 
to indicate a radical difference of origin and nature. This idea, however, was completely 
dispelled by Cox's report in 1879, for all geologists have agreed with him in stating 
that the red cement was derived from the blue by the simple action of oxidation. 

The conglomerate contains a certain amount of pyrite throughout, but this is much 
more abundant near the " bottom " of schist rock than elsewhere. A good deal of this 
pyrite, as shown by crystals with sharp angular form on the surface of boulders, is of 
secondary origin. Some calcite is also present in the conglomerate.* 

No pebbles or boulders of any rock of igneous origin were found in the conglome- 
rates. As stated before, the actual direction of the fault-plane is 111° at its north- 
western end and 148° at its south-eastern end. The original surface of the fault-plane 
was without any irregularity, and at first was quite smooth, but the rapid decay of the 
schist and the action of rainfall have allowed but little of it to remain. The schist 
is much changed for a thickness of about 4 in. The change is due to the com- 
minution of the schist-material, which loses all its structure and acquires a black 
colour. 

The surface of schist on the downthrow side is uneven, with small gutters, quite 
similar to the bed of a river flowing across the schist at the present day. The strike 
of the schist round the Bluespur conglomerate is most variable ; about the middle of 
the fault-plane it is 215°, with a dip of 16° to the north-west. 

Wether stones. 

The large area of conglomerates at Wetherstones has never been exactly defined 
in previous reports. Considerable difficulty was encountered in finding its exact limits. 

* Oral communication from Dr. J. Henderson. 



63 

The surface of the ground is so deeply covered with clay, while vegetation and crops 
mask it so completely, that without the time and labour of digging prospect-holes 
it is not possible to be quite certain as to its precise boundary. It is, however, pro- 
bable that the careful work done in this area leaves no large room for error. The deposit 
is of much larger size than that of the Bluespur, for it extends over about two square 
miles. Its structure too is far less simple. A large part of the area was originally 
flat, and is now covered with tailings from sluicing operations. At its northern end 
the conglomerate area is bounded by a fault as sharp, smooth, and distinct as at 
the Bluespur. The plane, however, is exposed for 80 yards only. At its west end 
schist is fomid on the downthrow side, and the gold-mining operations have naturally 
left this rock alone. At its eastern end it encomiters a thrust-plane, which was appa- 
rently of earlier age than the fault-plane. The fault-plane has a bearing of 109°, and the 
thrust-plane bears 155° ; they therefore intersect at an angle of 46°. The amount of 
movement along these planes cannot be stated. 

The sluicing operations carried out by the Golden Crescent Company have revealed 
the presence of four faults on the north-western side of the conglomerate. These 
faults have the following bearings: 134°, 142°, 146°, 139°; and hade from 40° to 
zero, the hade being generally directed to the south-west. The faults appear to be 
of short lateral extent, and the amount of throw could not be estimated. It is possible 
that some of these fractures n\ay be thrust-planes, but whether this is so cannot be 
definitely stated. The occurrence of so many faults suggests that other parts of the 
boundar}^ of the conglomerate may have a similar structure, but, apart from the 
relatively low position of the conglomerate with respect to the surrounding schist, no 
evidence of such structures could be found. 

On the west side, at the extreme north end of the conglomerate area, the " cement " 
has been sluiced ofi the schist on which it rested. This schist bottom has the same 
irregular surface as at the Bluespur. Its average bearing is 162°, and its slope to 
the north-east is 15°. 

The conglomerate is distinctly stratified, in a manner similar to that at Bluespur. 
The stratification is parallel to the slope of the western schist bottom, and is t]iere[ore 
15° north-east. The eastern side, however, shows some change, for some of the deposit 
exposed near the school, close to the schist hills on the east side of the basin, has 
a strike of 220° and a dip of 35° south-east. As the conglomerate area is 800 yards 
wide at this point the cement* would extend to a depth of 650 ft. if the dip were main- 
tained uniformly. Such an increase in dip as that noted near the school, of course, 
means a considerable increase in thickness. On the other hand, such a structure as 
the thrust-plane which is seen in the Crescent Claim brings the bottom of the cement 
85 ft. nearer to the surface of the ground. These considerations indicate that its 
thickness is about 565 ft. This has never been full/ tested by boring, though bores 
have been made at several points. Only one of these, however, extended to the 
deeper ground. This bore was situated about 100 yards to the west of the point 
where the small bridge on the Wetherstones Road is situated. At this point the cement 
was found to be 500 ft. thick. It is thus obvious that an enormous amount of cement 
is present in the Wetherstones district. If the average tliickness is taken at 200 ft., and 
the area at two square miles, the total quantity of cement must be 413,000,000 cubic 
yards. 

The material of the cement at Wetherstones is quite similar to that at the Blue- 
spur, at any rate in its lower strata, which are the only portion of the formation 



* Owing to the frequent use of the term "cement" inverted commas are omitted in this paragraph, and 
also, as a rule, on later pages. 



64 

represented in the Bluespur deposit. The schist pebbles and boulders are far more 
numerous than those of greywacke. The so-called jasperoid boulders are about as 
frequent, and the boulders are all cemented together by a fine bluish material which 
is evidently comminuted schistose matter. Here and there pieces of Wood occur which 
are often wholly or partly converted into coal. Here, as at the Blue.spur, near the 
bottom of the cement there is much pyrite, most of it secondary in origin. The upper 
strata of the cement, however, show features not now seen at the Bluespur. They 
consist largely of fine quartz, sands and grit, and interstratified with these are seams of 
impure Ugnite. In several places near the margin of the cement these sands have, 
owing to the deposition of secondary silica, become consohdated into hard flinty concre- 
tionary boulders, often of large size. These boulders, locally called " chinamen," are quite 
analogous to the sarsen stones of EngHsh geologj-, and, hke them, often indicate the 
previous extent of the deposit of quartz-grits after the greater part of it has been removed 
by processes of erosion. In the Wetherstones area they are most numerous at the south- 
west end, and at the heads of the small gulUes in the Golden Crescent Claim. The 
occurrence of the quartz-grits and sarsen stones in the upper members of the Wether- 
stones cements is a fact of considerable importance in connection with the question of the 
age of these deposits. 

The Wetherstones conglomerates are certainly the products of fluviatile, not of 
glacial, deposition. This is clearly shown by the stratification, the rounded forms of 
the component boulders, the absence of striated and faceted pebbles, and also by 
the presence of interstratified beds of lignite. 

The gold-content of these cements is perhaps rather less than that of the Blue- 
spur, though this is not certain. The gravels of the original flat derived from the 
cement were hardly less productive than those of Gabriel's Gully, which were derived 
from the Bluespur. On the other hand, it has been found less profitable to tunnel 
the Wetherstones cement for the alluvial gold on the bottom than was the case at the 
Bluespur. This, however, is probably due rather to the relative difficulties of mining 
in such low-lying deposits than to a difference in richness. 

Forsyth. 

The cement-deposit is well exposed in the railway-cutting near the railway-station, 
and it can be traced continuously from that locahty to Paddy's Point and to some 
height on the slopes of the hills bounding the small valley on the south-west side. 
The deposit has been worked by individual diggers over a considerable portion of the 
area, and at Paddy's Point in particular good results were obtained, as well as along 
the valley of the small stream which flows south-east through the area to join the 
Waitahuna River. No work has been done for a long period, and no attempts have 
yet been made to work the deposit on a large scale, mainly because all the available 
water is being used at the Bluespur, Wetherstones, and Waitahuna. 

In a cutting half a mile to the south-east of the railway-station the boundary 
of the " cement " is seen to be a fault -plane similar to those at Bluespur and 
Wetherstones. In this case it strikes 166°, and dips 27° south-west. It is impossible 
to make any statement as to the throw of the fault, as the exposure is quite small. 
Elsewhere the nature of the contact between the schist and the " cement " is not 
seen, but the relatively low level of the cement compared with that of the surrounding 
schist suggests that there is a continuous strong fault bounding the deposit on its 
north-east side. 

The materials and nature of the Forsyth deposit are quite similar, so far as can 
be seen over the greater part of the area, to those of the Bluespur and Wetherstones 
deposits. It is, however, noticeable that at Paddy's Point, and at many places on 
the south-west margin of the deposit, there are, as at Wetherstones, a large number 



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of " chinamen " — that is, quaitzose sand or gravel, the component grains of which are 
cemented into a particularly hard mass by the deposition of a siliceous substance, which 
under the microscope has the structure of chalcedony. These boulders are often of 
large size, and, hke many concretionary objects, of a most irregular shape. They 
have also a particularly smooth exterior surface. The occurrence of these boulders in 
what is apparently the uppermost layer of the " cement " is considered to be a 
matter of great importance in connection with the discussion of its age. 

Waitahuna Gully. 

This area is about two miles distant from the township of Havelock (Waitahuna), 
and is undoubtedly the source of the alluvial gold which was worked almost as soon 

PLAN OF 
WAITAHUNA GULLY WORKINGS 

Scale of Chains 




Border of Cement 




SAILORS CULLY 
CMC. 



\ 



\ 



/ 



V ..-'■ 



as the auriferous gravels of Gabriel's Gully. The cement occurs on the south-east 
side of the gully, and its outcrop measures about half a mile across. It rises high 
on the hills on the south-east, while on the north-east side it is bounded by a great 
fault similar to those at Bluespur, Wetherstones, and Forsyth. In this case the sluicing 
operations have bared the fault for a distance of nearly half a mile, and at one place 
to a depth of 200 ft. The fault strikes 167° near its most southern exposure, and 148° 
where sluicing is now in progress. In other words, it bends 19° in a total distance of 
650 yards. 

On the south-west side the deposit rests on an eroded bottom of partly altered 
greywacke, worn into small ridges and troughs in a manner similar to the bottom 
at the Bluespur. The face of the fault has a dip of 34°, while the bottom has a 



56 

slope of 20°. If these slopes are maintained across the deposit the total thickness 
must be 600 ft. 

The material of the cement is generally indistinguishable from that of the other 
cement areas that have been described. There is, however, a noticeable difierence 
in the nature of the boulders on the southern and south-western fringe. Here there 
is a far greater proportion of greywacke boulders than elsewhere, a fact that was 
noted by McKay, who reasonably suggested a local origin for much of the cement 
because the rock surrounding this basin is but httle changed from the typical grey- 
wacke condition. One or two " chinaman " boulders only were seen on the south-west 
border. On the north-west side — that is, in the valley of the Waitahuna Gully stream 
— the margin of the cement is not to be seen. It certainly does not extend as far as 
the hills that rise from the opposite bank, and, as appears from the plan, it does not 
extend far into the gully-floor. The large accumulation of tailings derived from the 
sluicing of the cement has raised the floor of the gully to such an extent as to 
obscure the boundary of the geological formations which may have been originally 
exposed. The cement has been sluiced all round the margin, and its surface has also 
been removed to a considerable depth, but about 16,000,000 cubic yards still remain 
to be treated. 

Adams Flat. 

This area mea.sures about a mile and a half in extreme length by three-quarters of 
a mile in extreme width. It is situated some three miles to the south-west of the 




Sketch Map of 
GLENORE. AND ADAMS FLAT 



— Scale — 



CHAINS 80 



40 

I I 1 I I 



2 MILES 



Cement. Early Cainoioic '^Ml Altered Greywacke. Mesozoic ?L — ] 

Mount Stuart Railway-station. The area is low-lying, with high ridges of greywacke 
rising to the south-west and west, and smaller heights to the north and east, where 
they are capped with a thick deposit of quartz gravels. 

The relation of this cement area to the rock - series around is not shown so 
clearly as in the other instances, for relatively little work has been done, and the 



67 

surrounding rocks have not been laid bare. The low-lying position of the cement 
certainly suggests that here, as in the other localities, it has been faulted down, and 
that it owes its preservation to this movement. If it has not been faulted it must 
occupy a deep erosion basin of earlier origin. 

The material of the cement can be distinctly seen in one or two places only, 
where it is much the same as in the other areas, though quartz pebbles and boulders 
appear to be more abundant, especially in the upper portions. A dredge is at present 
employed on the south-east portion of the deposit. Most of the superficial part of the 
deposit has been worked in a small way by individual miners, who are reported to 
have done well. No supply of water has ye been obtained for working this deposit 
on a comprehensive scale, and it is probable that none will be available until the 
cement areas which lie farther to the north-west have been exhausted, a result that 
will not be achieved, at the present rate of progress, in less than two centuries. 
" Chinaman " boulders, already referred to in connection with other cement areas, 
occur here on the south and west borders of the conglomerate area. 

Glenore. 
Here there is a patch of auriferous conglomerate or " cement " in the floor of 
the south branch of the Tokomairiro. As at Adams Flat, its low-lying position prevents 
it from being exposed to such an extent as to reveal the structure of the basin. The 
area is at the present time being worked by a dredge which operates on a cement 
bottom. It is not possible to define the boundaries of this basin, but it is probably 
of small extent. It will always be difficult to work, even if a sufficient supply of 
water is available. The hills of greywacke rock which surround the deposit suggest 
that the cement is faulted down, as in the other areas, but of this there is no proof. 

The Taieri " Moraine" 

Since the Bluespur cement and, infereiitially, similar areas of auriferous conglomerate 
have by various geologists been correlated with the great deposit of breccias forming the 
south-east boundary of the Taieri and the Tokomairiro Plain it was considered advisable 
to visit these localities in order that a comparison might be made between them. There 
appears to be no doubt that these are similar fomiations, though their bulk is vastly 
greater than that of the cement areas, and the material of which they are composed is 
somewhat less compact, though this may be due to the fact that the inner portions of 
these deposits have not been exposed by mining operations. These massive conglomerates 
form part of a nearly continuous range of hills, 500 ft. to 1,000 ft. high, extending from 
Allanton in a south-west direction to Mount Miser}'. 

Their relation to the schist is not displayed in many places. It is poorly seen ' on 
the south side of the Taieri Bridge, but more clearly at the mouth of a .small stream 
opposite Milburn, about four miles north-east of Milton. Here the schist is much 
crushed and contorted, and has actually been thrust over the gravels for some dis- 
tance.* The same crushed and contorted condition of the schist is seen at the 
Milton brickworks and at the south end of the bridge over the Tokomairiro 
River. At Mount' Misery- the gravels ri.se to a height of 1,000 ft., where they are 
covered by a capping of quartz • gravels cemented by iron-oxide into a solid mass 
of material resembling the " chinaman " boulders, though with a somewhat ferruginous 
cement. 

The conclusion was reached that the material of the Taieri " moraine " is of the 
same nature as the Bluespur and other deposits of cement, and that it probably has 



*See also page 26. 



58 

the same origin and is probably of the same age. It has also, in one place at least, 
been partly covered by schist moved bodily along a thrust-plane. 

Origin of the " Cement." 

On a previous page a short summary has been given of the opinions that have 
been held as to the origin of the cement. It is there stated that Hutton, Ulrich, 
Cox, Park, and Rickard all ascribed it to glacial deposition, while McKay ascribed it to 
ordinary fluviatile action. The latter origin seems to be supported by overwhelming 
evidence, which may be summarized as follows : — 

(1.) The deposit is stratified. 

(2.) The component pebbles are well rounded. 

(3.) Leaf fossils and tree-tnmks are embedded in the material. 

(4.) There are no striated or faceted pebbles. 

(5.) The glacially worn rock-basin in which Hutton stated that the deposit 
lay is shown, now that the sluicing-work has laid the rock bare, to be 
the slickensided surface of a great fault-plane. 
These facts appear to force any observer to the conclusion that the material is due 
to deposition by a river. The examination of the Bluespur cement was made in the 
company of Mr. C. T. Trechmann, a well-known writer on the glacial deposits of the 
North of England, and he permits the statement to be made that he fully agrees as to 
the fluviatile origin of this cement. Subsequently the author, in company with Mr. Trech- 
mann and Professor H. B. Gregory, of Yale University, paid a visit to the typical 
exposures of the Taieri " moraine " at Henley. The similarity of this to the cement 
was at once apparent, and after a close inspection it was agreed that it was erroneous 
to ascribe a glacial origin to this mass of gravels. This conclusion is opposed to 
the statements of previous observers of the deposit, for they have all regarded it 
as glacial, with the exception of McKay, who was non-committal on the question. 
Comparison with the Bluespur deposit, which is clearly of fluviatile origin, and the 
opinions of the two distinguished authorities named above have resulted in the sup- 
posed moraine being classed in this report as a river deposit. 

Palceontology and Age of the Cement. 

The Bluespur is the only cement-deposit that has jaelded any fossil remains. 
These consist of leaves and leaf-impressions embedded in the finer beds, and of wood 
which has been found occasionally at various levels. The leaves and leaf-impressions 
are not well preserved, but one of them is sufficiently distinct to refer without any 
doubt to Aralia Tasmani Ettingshausen,* which occurs at Shag Point and elsewhere 
in coal-measures. The wood was in the form of a large trrmk 25 ft. long and 1 ft. 6 in. 
in diameter. This was preserved by Mr. H. L. Darton, and the author is greatly 
obliged to him for specimens. Sections of the wood cut in a radial direction showed 
very distinct bordered pits. These are arranged in a manner similar to those of 
Podocarpium dacrydioides Ung. Their nature and arrangement is quite different from 
those of Araiwaria Haastii Ett., Dammara Oweni Ett., and Araucarioxylon novas 
zeelandii Stopes. Tangential and transverse sections showed no characters that could 
be regarded as determinative, though the medullary rays in the former are longer 
and less numerous than in the species named. The wood is therefore referred to 
Podocarpium dacrydioides Ung.f Ettingshausen refers the Shag Point flora, in which 



* Von Ettingshausen, C. : Beitrage zur Kenntniss der fossilen Flora Neuseelands, K. Akad. Wissench., 
Wien, vol. liii, part 1, 1887, p. 169, and Taf. v, figs. 13, 14 ; also translation by C. Juhl, Trans. N.Z. Inst., 
vol. xxiii, 1891, p. 278, plate xxviii, figs 13, 14. 

t Raise der Novara, Geologischer Theil, Band i, Abt. 2, p. 13. 



59 

Aralia Tasmani occurs, to the Eocene period (see, however, page 62). Podocarpium 
dacrydioides is not definitely placed in any of the geological periods. The wood is 
said to present characters intermediate between those of Podocarpus and Dacrydium. 

It thus appears that this meagre record of fossil plants indicates that the cements 
were probably deposited at a period contemporaneous with the European Eocene. 

Economic Geology of the Cement. 

The conglomerates or cejnents have been the most productive gold-bearing deposits in 
the district, and they probably equal any other auriferous deposit in the South Island in 
yield of gold. In making this statement the produce of gold from Gabriel's Gully and from 
Munro's Gully is reckoned as part of the Bluespur metal, as it is certainly derived from 
this, and has been transported a very short distance from its point of origin. It has 
been estimated that gold to the total value of £5,000,000 has been obtained fi'om the 
two areas of cement at Bluespur and Wetherstones, together with their alluvia in the 
adjacent gullies. This estimate, however, is not more than a guess. So far as the 
actual cements are concerned, they were first worked by individual miners and small 
parties, but afterwards by small companies. These early companies generally worked 
the richest part of the cement only ; this was found on the schist bottom forming the 
soutb-west side of the Bluespur. Regular mining methods were employed, and the 
lower strata of the cement were almost bodily extracted. So rich was this detrital 
matter that it yielded profitable returns when treated in stamping-mills like ordinary 
auriferous quartz. A specimen of this rich bottom cement is preserved at the Duncdin 
Museum. Only the lowest stratum of the cement was rich enough to be crushed, 
and when this was exhausted the milling treatment had to be abandoned. The surface 
of the Bluespur, where the cement had been disintegrated by atmosplioric influences, 
was removed by sluicing. The great mass of blue unoxidized cement which remained 
after removal of its base by mining, and of its superficial portions by sluicing, has 
an average value of about 8d. per cubic yard, and this has required different treat- 
ment. The small sluicing companies gradually declined, for the profitable disinte- 
gration of the tight cement required greater water pressure and power than they 
possessed. 

In the year 1887 the amalgamation of the Bluespur companies was arranged, 
and in the following year the Bluespur Consohdated Gold-mining Company, with a 
capital of £130,000, was formed. This company acquired nearly all the ground and 
nearly all the water-rights, which included races extending as far as the Waipori 
River, with a total length of 150 miles. At first this company worked the 
taihngs, which had been indifferently treated by the small companies, and obtained 
satisfactory returns. In 1892 the company began working the cement seriously. 
An attempt was made to crush this with rollers, but was not satisfactory, for 
the pebbles in the cement are of varying size, some having the dimensions 
of boulders and attaining a diameter of 18 in., whilst the gold is in the fine- 
grained matrix. Thus in order to extract the gold the whole of the material had 
to be reduced to a fine condition. Accordingly this method was costly, and was there- 
fore soon abandoned. The most economical method of treatment was found to be 
breaking up the cement with large charges of explosive, and subsequently further 
reducing it by means of jets of water under wery high pressure. Treated in this 
way the cement yielded a profit ; but as the comminuted material had to be raised over 
the accumulated heaps of taihngs by hydraulic elevators, a large supply of water 
under high pressure was required for this purpose. In practice it was found that the 
available water did not allow of sufficiently rapid treatment to provide any but a 
small dividend on the large capital ; and after some litigation with the owners of the 
adjoining claim, who were working the north-west portion of the deposit, the Consohdated 



60 

Company in 1913 went into liquidation. Its property was bought by the G-abriers Gully 
SKiicing Company, which has been treating taihngs with success since it began work. 
The tailings have continued to yield gold for such a long time because the cement when 
first treated was not reduced to a sufficiently fine state to allow all the gold to be 
separated. Exposure to atmosphere and water has, however, caused the small frag- 
ments of cement to disintegrate, and the gold contained in them is easily saved when 
thus freed. 

The total amount of cement originally present at the Bluespur may be roughly 
estimated at 10,000,000 yards. Perhaps over three-quarters of this has been removed, 
and 2,250,000 yards remain. A large amount of gold is stored in this cement, the 
treatment of which, if worked at the same rate as by the Consohdated Company, 
would require at least ten years. 

The Wetherstones area is many times larger than the Bluespur. Comparatively 
little of the bottom layers has been mined, partly because of the expense and difficulty 
of pumping, and partly because of indifierent management. The returns of the Golden 
Crescent Company, which is now working this area of cement, show that the gold- 
content is much the same as that of the Bluespur. The amount of gold contained 
in this large quantity of cement is enormous, and unless means of treating it more 
rapidly are devised it will last for at least two> hundred years. The greater part 
of this deposit, however, is deep ground, and catmot be worked so as to give 
remunerative returns by the present methods. 

At Waitahuna Gully the cement is of much the same value as at Bluespur and 
Wetherstones, but the bottom has not been driven out to a great extent ; thus, as 
at Wetherstones, most of the richest part still remains. At the present rate of 
progress this deposit will certainly last for one hundred years. 

With the exception of a certain amount of tunnelling at Paddy's Point in 
the Forsyth area, and the dredging at Adams Flat and Glenore, the other areas of 
cement are practically untouched. 

The amount of water at present available does not allow of more rapid treatment 
than is now being employed for a yield of £15,000 worth of gold each year. Practically 
all the water in the district which flows naturally at a sufficient height to give the 
necessary pressure is now in use, and it is thus evident that with the present methods 
gold returns cannot be materially increased. If by mechanical methods the supply 
of water could be multiplied several-fold, or cheap power could be obtained, or if some 
other comprehensive means could be devised for breaking down the cement, the gold 
returns could be proportionately increased, and could be maintained at the greater 
rate for a long period. 

From what has been said it is evident that in the cement-deposits of the Tuapeka 
district there is an immense reserve of auriferous fluviatile gravels, which contain in 
the aggregate at least £5,000,000 worth of gold. The proper working of these deposits 
requires a comprehensive scheme of water-supply and a corresponding great capitahza 
tion. The success at present attending the operations of the Gabriel's Gully, Golden 
Crescent, and Sailor's Gully companies, which are working on the cement on as large 
a scale as their capital and water-supply permit, only emphasizes the probabiUty of 
success that would attend the employment of greater power and more water. 

(2.) Quartz-grits. 
Distribution. 

These fine gravels and sands are locally known by the strangely incorrect name 
"granite." Their most typical exposure within the Tuapeka district is to be seen 



Plate XII. 




A. " Chinaman "' Bouldkr. Tuapeka Vai.lev. 




B. •Chinaman" Boulder, Tuai'kka Valley. 



QpoL Bull. Xo. 19.] 



[To face page 60. 



61 

at Manuka Hill. Here the gravels are 70 ft. thick, and display current bedding 
with especial clearness. The material is fine-grained, and in places is simply a sand. 
Certain layers have become cemented by iron-oxide and silica, thus giving rise to 
" chinaman " boulders. They are, however, brown as compared with typical examples, 
which are characteristically white. A similar deposit caps practically all the hills 
between Manuka Hill and the Tokomairiro Plain. Farther north it forms the top of 
Table Hill, but does not occur near Lawrence, though near Havelock it forms the 
crest of Coghill's Hill, and caps the hills noi-th of Waitahuna Gully. Typical " china- 
man " boulders, obviously the relics from the denudation of a similar deposit, are, 
however, found in various localities. Several are to be seen at Trig. F, 1,200 ft. 
above sea-level, two miles south-east of Lawrence. There is a large development 
on the south-east side of the Tuapeka valley, four miles from Lawrence. Here the 
" chinaman " boulders are particularly large and massive. It has been previously 
stated that similar concretionary objects are found on the west of the Wetherstones 
and of the Forsyth cement areas. 

There are other areas of quartz-grits in the Tuapeka district, which, however, occur 
at low levels. One of these is within the boundaries of Lawrence, where it occurs over 
the area of the old racecourse. Quartz-grits are found again at Evans Flat, from 
which place they rise to the slopes of Munro's farm lying to the south-east. They 
occur again on the railway-line one mile to the north-west of the tunnel through the 
Big Hill. In the last three localities the quartz-grits are associated with seams 
of lignitic coal. The upper strata of the Wetherstones cement and of that at 
Forsyth are strikingly similai- to the quartz-grits, and may be referred to this 
formation. In the extreme south-east of this district, south and east of Adams 
Flat, on the hilltops, and also round Glenore there is a great development of the 
quartz-grits. 

The well-known area of quartz-grits at Coghill's Hill, near Havelock, consists of a 
deposit 50 ft. thick, and, as in other places, it has become cemented into " chinaman " 
blocks to a large extent. There is also a relatively large area on the north-west 
side of Waitahuna Gully, on the crest of tlie hill. Here there are very few 
" chinaman " boulders, but the gravels have been worked by diggers at various 
times. At Waitahuna Flat the quartz-grits have the same position as at Evans 
Flat, where they constitute the false bottom on which the dredges worked. 

McKay assigns a marine origin to these quartz-grits. If that is the case they 
were certainly deposited in shallow water. The cross-bedding that they frequently 
show and their very nature seem to imply that they were formed on a beach. 

Relation of Quartz-grits to Cements. 

The relation of the quartz-grits to the cements is a matter that has given rise 
to a considerable amount of discussion. Cox* placed the quartz-grits above the 
cements. This was the position also adopted by McKay, and is the position assigned 
to them in this report. The reasons for this are as follows : — 

(1.) At Wetherstones and Forsyth the upper strata of the cement appear to be 
identical with the quartz-grits in other localities. 

(2.) At Coghill's Hill there is a thin layer of cement between the schist and the 
quartz-grit. 

(3.) At Waitahuna Gully and at Adams Flat the quartz-grits occupy a much 
higher position than the cements in areas immediately adjoining. This, however, 
may possibly be ascribed to faulting. 



* Cox, S. H. : Rep. of Geol. Explor. during 1878-79, No. 12, 1879, p. 45. 



62 

(4.) The best evidence is found outside the Tuapeka district, in the Tokomairiro 
Gorge and at Mount Misery. In the former locality the relation is seen in two places 
on the left bank of the Tokomairiro River just below the second bridge from Milton, 
where the road to Shag Creek rises to the old coal-pits. Here all the Cainozoic 
rocks are faulted down, but the quartz-grits and coal-beds are clearly seen to rest on 
the conglomerates, which are here cemented into a solid resistant rock. The second 
locality is on the right bank of the Tokomairiro, on a spur 400 yards before reaching 
the Waronui coal-mine railway-crossing. Here conglomerates equivalent to the cement 
form the lowest part of the spur, but at a height of 100 ft. above the river-level they 
are succeeded by quartz-grits, which at a higher level are cemented by iron-oxides 
into hard boulders of huge size. At Mount Misery, 1,094 ft. high, the lower 1,000 ft. 
are formed of conglomerate which is believed, without doubt, to be the equivalent of 
the cement. This is succeeded by quartz-grits, which form approximately the 100 ft. of 
the crest. Here again the quartz-grits are cemented by secondary silica and iron-oxides 
into large masses of resistant rock. In these localities at least there can be no doubt 
that the cements or conglomerates are of greater geological age than the quartz-grits. 

The present bulletin therefore merely emphasizes the opinions held by Hutton, 
Cox, and McKay* as to the relative age of these formations. On the other hand. 
Park classes the Bluespur and other cements, together with the conglomerates of the 
so-called Taieri moraine, in the deposits of the Pleistocene ice age, which are immensely 
younger than the quartz-grits. 

Age of Quartz-grits. 

Within the Tuapeka district no fossils whatever were found in the quartz-grits, nor 
have any been found by previous observers, and thus the only indication as to their 
age is the fact that they rest stratigraphically with conformity on the cements, and that 
at the Bluespur Aralia Tasmani Ett. is present in the leaf-beds. The Shag Point beds, 
where 'this plant fossil occurs typically, is classed by von Ettingshausen in the Eocene; 
but certain marine fossils found by McKay in beds stratigraphically higher at Shag Point 
have caused him, and subsequently all others, to class the Shag Point beds as Cretaceous. 
This evidence indicates that the quartz-grits are not younger than the oldest Tertiary. 
Further evidence is found some twenty miles to the south-east of this district, at 
Wangaloa. It has already been stated that the conglomerates and quartz-grits can be 
followed to the Waronui coal-pit. From this point there is a clear continuation southward 
along the coast-line, and at Wangaloa the beds exposed at Mitchell's Point are admittedly 
in an horizon slightly above the grits. These beds at Mitchell's Point have long been 
known to be fossiliferous, but the fossils have been classified within the last year only.f 

Since the paper quoted below appeared in the " Transactions of the New Zealand 
Institute " specimens of the more difficult species of Mollusca have been sent for 
examination to M. Maurice Cossmann, the celebrated palaeoconchologist of Paris, and to 
Dr. T. Stanton, of Washington. These steps were taken because no specimens of 
similar species were available in New Zealand for comparison ; and the imperfect 
preservation of these fossil forms renders it difficult to identify them from descriptions, 
without the experience derived from the handhng of species of a similar nature. 

The examinations made by these speciaHsts somewhat changes the former identifica- 
tions. M. Cossmann says that the two species referred to Avellana really belong to the 
genus Gilhertia, which occurs in the Palaeocene of the Paris basin and perhaps in the 
Maestrichtian. 

Dr. Stanton kindly examined the two species provisionally regarded as Euthriqfusus, 
and refers one of them to the genus Heteroterma, which is restricted to the Lowest 

* Hutton, F. W. : " Geology of Otago," 1875, p 93. Cox, S. H. : Rep. of Geol. Explor. during 1878-79, 
No. 12. 1879, p. 45. MoKay, A. : " Older Auriferous Drifts of Central Otago," 2nd ed., 1897, p. 94. 
t Marshall, P. : Trans. N.Z. Inst., vol. xlvii, 1915, p. 114. 



63 

Eocene (Martinez) of California. The other is placed by him in the genus Perissolax, 
which occurs in the Upper Cretaceous (Senonian) of California only. It thus appears 
that there are two Cretaceous genera — Pugnelliis and Perissolax* — and three species that 
indicate the Lowest Eocene. 

The whole collection amounted to fifty-four species. So far as the geological 
horizons they indicate are concerned, they may be classed as follows : Cretaceous, 
4 per cent. ; Eocene, 6 per cent. ; new species, but belonging to genera which occur 
in the New Zealand Miocene, 36 per cent. ; species that occur in the New Zealand 
Miocene, 54 per cent. ; Recent species included under the last head, 15 per cent. 

A discussion of the age of the beds that contain such an association of Mollusca is 
not required here, but it can be generally stated that at the latest a very early Tertiary 
horizon is certainly represented. It thus appears that there is palseontological evidence 
of a similar age for the cements and the quartz-grits. 

Economic Geology oj the Quartz-grits. 
Within this district the quartz-grits have been found to be auriferous in several 
places, but only at Manuka Hill, at Coghill's Hill, and north of Waitahuna Gully have 
gold-mining operations been undertaken. Notwithstanding that the supply of water was 
small and the pressure slight, a fair amount of gold was obtained. There is a large 
area of the auriferous grits at Manuka Hill, but most of this is now a railway reserve, 
and in it a ballast-pit for supplying the railway-line has been opened. It is not likely 
that the quartz-grits will supply a very large amount of gold. Their position on hill- 
tops makes it a matter of difficulty to obtain the water-pressure required for sluicing 
purposes. The small deposit on Coghill's Hill was said to be sufficiently rich to pay for 
carting the material to the Waitahuna River for treatment. The grits on the north side 
of Waitahuna Gully also provided a considerable amount of gold. 

(3.) Volcanic Rocks of the Waitahuna Series. 

No volcanic rocks have previously been described from this series within the area 
dealt with in this bulletin. There is, however, a large area of volcanic rock extending 
from Trig. K in the Tokomairiro Survey District to within a mile of the Canada reefs, 
a distance of three miles and a half. It has weathered throughout the greater part of 
its thickness, which is about 50 ft., into large extremely hard and tough spheroids. The 
most conspicuous component is olivine, in large rounded grains very slightly serpentinized. 
Feldspar is present in large quantity. It appears to belong almost entirely to anorthite, 
as would be expected from the large percentage of lime shown by analyses of the rock. 
Augite is present in amount that is quite subordinate to the olivine. A good deal of 
ilmenite is present. There is also a considerable amount of nepheline, which was the 
last mineral to form, and fills spaces between the feldspar and other minerals. There 
is also a small amount of apatite. 

The rock is thus clearly a nepheline-basanite, with a doleritic texture. It is certainly 
related to the nephelinites of the Waihola district, previously described by Marshall. I 
It differs from them in its much smaller amount of nepheline, and consequently, from 
a chemical standpoint, in the lower percentage of alkali. It is remarkable that the 



* The genus Perissolax had previously been recorded from California only. The pre.sent specie.s is stated 
by Dr. T. W. Stanton in a MS. letter to be very similar to P. brevirostrin Gabb of the Chico or Upper 
Cretaceous formation of California. Cossmann, who in a MS. letter also admits the correctness of classifying 
the present form with Perissolax, places the whole genus in the Senonian ("Essais de Paleoconchologie 
comparee," 4<'. liv., 1901, p. 72). A more recent publication by Roy E. Dickerson, however, mentions species 
of the genus as occurring in the Martinez and Tejon (Upper and Lower Eocene) as well as the Chico (Roy E. 
Dickerson, Bull. Dep. Geol. Univ. Calif., vol. viii, No. 6, 1914, p. 97 ; also vol. ix, No. 17, 1916, p. 421). The 
species in these latter strata are, however, less similar to the Wangaloa species than is P. brevirostris Gabb 
from the Chico. The statement made in the text evidently needs some slight qualification. The presence 
of Perissolax suggests either an Upper Cretaceous or a Lower Eocene age, while the features of this particular 
species incline the indication towards the former alternative. 

t Marshall, P. : " Nephelinite Rocks in New Zealand." Trans. N.Z. Inst., vol. xliv, 1912, p. 304 



64 



percentage of potash is much higher than that of soda, a relation that is paralleled in 
the available analyses of rocks of this class by the nephelinite of Regatta Point, 
Tasmania, alone. 

The following table shows its composition as compared with that of similar rocks : — 









(A.) 


(B.) 


(C.) 


CD.) 


Silica (SiOJ 






. 36-00 


42-19 


48-90 


43-60 


Titanium dioxide (TiOj) . 






. 2-50 


0-87 




1-37 


Alumina (AljOg). . 






. 14-51 


18-00 


16-51 


9-87 


Ferric oxide FejOj) 






. 7-19 


7-73 


0-57 


7-43 


Ferrous oxide (FeO) 






. 10-28 


8-67 


11-58 


5-40 


Lime (CaO) • . . 






. 12-95 


9.27 


9-25 


14-26 


Magnesia (MgO) . . 






. 4-02 


7-06 


7-10 


7-18 


Potash (KjO) .. 






. 3-04 


1-05 


1-99 


3-81 


Soda (Na^O) 






. 3-61 


3-15 


0-80 


1-74 


Phosphoric anhydride (PjOj) 




. 1-56 






1-85 


Loss on ignition . . 


• 




. 4-40 


1-35 


3-50 


101 



100-06 99-34 100-20 97-52* 

(A.) Coarse nephelinite. Lake Waihola. Analyst : P. Marshall. (B.) Fine nephelinite. 
Clarendon. Analyst : A. R. Andrew. (C.) Basanite, Canada reefs. Analyst : G. E. Hyde. 
(D.) Nephelinite, Regatta Point, Tasmania. Analyst : Paul. 

Another volcanic rock was found some years ago during gold-washing work in a 
small creek near the top of the Waitahuna Heights, not far from the cinnabar lode. 
The rock is extremely vesicular. In section it is seen to consist mainly of long feldspar 
crystals much twinned, and for the greater part labradorite. Minute crystals of augite 
and of iron-ore form the groundmass. There is one grain of olivine present in the 
section. The rock is a vesicular basalt. The author was informed that the outcrop is 
now completely covered with gravel, and was therefore unable to make any observations 
in regard to its geological age. 

Conditions of Deposition op Waitahuna Series. 

It has already been stated that the cements are of fluviatile origin, and it follows 
that the patches that are now preserved represent portions of the bed of a large 
Cretaceous or Early Tertiary river. This river flowed from the schistose districts of 
Central Otago which had already undergone prolonged and immense denudation since 
the Triassic period. Its waters consequently transported an immense amount of schist 
boulders and other detritus, together with much gold. A gradual sinking of the 
Cretaceous land-surface at the close of this period caused the channel to become 
filled with the detritus transported by its water, and amongst this material was 
scattered the gold which was brought down with the schist and somewhat concentrated 
by the river-action. The sinking of the land-surface continued, and the region was 
invaded by the sea, and on its beach and shallow floor were deposited the quartz- 
grits. Probably these grits were subsequently covered by other marine deposits, but 
of this there is no indication nearer than Milburn, some ten miles east of the Tuapeka 
district. Elevation then took place, associated with much faulting, and as a resxilt 
of the latter some portions of the old river-channel were brought to such a low level 
that they largely escaped the action of denuding agents that at once commenced to 
reduce the altitude of the emerged land and to remove the loose unconsolidated deposits 
formed whilst the depression lasted. These portions of the old river-valley gravels 
now constitute the important formations of auriferous conglomerates or cements. 



* The original analysis includes additional constituents. 



65 



CHAPTER VII. 



PLEISTOCENE DEPOSITS. 



Page 
Distribut ion . . . . . . . . 65 



Waipori Quartz Gravels 
Origin and Age 
Economic Geology 

Mitchell's Flat " .. 



65 
66 
66 
67 



Page 
Verier Burn . . . . . . . . 67 

Gravel Terraces of Molyneux and Tua- 

peka Rivers . . . . . . 69 

Molyneux River Terraces . . . . 69 

Tuapeka Tliver Terraces . . . . 69 



Distribution. 



Gravels are but poorly developed in the valleys of even the larger streams, though 
at certain points these valleys, as previously stated, expand into moderately large 
basins, the floors of which are completely covered to a depth, in most cases, of less 
than 20 ft. Generally it appears to be impossible to discriminate between those 
gravels that may be of Pleistocene age and those that are truly Kecent. The only 
suggestion of a greater age for some of the gravels is the position of those on the old 
flood-plain of the Moljmeux, the terrace gravels along the lower portion of the Tuapeka 
River, and the large extent of gravel downs on the south-east side of the Waipori 
River and in the valleys of Pioneer and Post Office (or Verter Burn) creeks. In the two 
former instances, however, the level of the stream is but little below the terraces, and 
the rivers have not yet reached their base-level, and are actively corroding their beds. 
In the case of the Waipori valley, the gravels owe thdr relatively high level to the fact 
that the Waipori has commenced to cut its gorge through the great barrier of schist 
which, in quite late geological times, was thrust up from the west, and thus dammed 
the river and for some time formed a lake of con.siderable size, on the floor of which 
the gravels were deposited. It is possible that much of this great gravel-accumulation is 
of Pleistocene age. 

Waipori Quartz Gravels. 

These extend over a length of ten miles from the Ballarat Gorge, three miles 
above the township, to the head of the main Waipori Gorge, where the power-station 
for the Diuiedin electric supply is situated. With the exception of the hill between 
the Waipori and Pioneer streams, the gravels extend to the foot of the Waitahuna 
Heights, a distance of three miles. The gravels consist mainly of quartz pebbles, for 
the most part angular, or at least but slightly water-worn. The material is a good 
deal current-bedded. There are occasionally some " chinaman " boulders, but these 
appear to be rolled, and do not occur in situ. The thickness of the gravels is con- 
siderable. At Johnson's claim, in the upper part of the Waipori Flat, the deep lead 
through the gravels has been excavated to a depth of 100 ft., and on the south side of 
the flat, near the township, a bore penetrated the gravels for a distance of 151ft. 6 in. 
apparently without reaching the bottom. Over the rest of the flat opposite the township 
the thickness of the quartz gravels proved to be less than 40 ft. The course of the 
deep lead through the gravels is hard to follow. This lead marks the channel of the 
Waipori River before the great thrust-movements, to which the elevation of Maungatua 
is due, caused the blocking of its outlet and the formation of a small lake-basin. 
WTiere this ancient channel has been exposed in Johnson's claim it hugs the southern 
side of the flat closely, and the same appears to be true opposite the township, but 

5 — Tu&peka. 



66 

elsewhere a series of bores will be necessary to establish its course. The bores that 
have been put down so far show that the flat is composed of alternating strata of 
fine gravel and sand with some clay. It is important to mention that the present 
course of the river is in places quite different from that of the deep lead. This is 
most noticeable at a point a quarter»of a mile above the Lammerlaw junction, where 
the present river flows through a small gorge in schist rock, which evidently constituted 
a lateral spur in the old valley. The same thing is repeated at a point one mile and 
a half below the Waipori Township. In both these instances the stream flows hard 
against the northern side of the old valley, while the quartz gravels cover a consider- 
able area of country to the south. It is evident that the quartz gravels at one time 
were thicker, and covered the lateral spurs to a greater depth than the actual height 
of the walls of the small gorges cut by the present river through these spurs. A small 
lateral deep lead joins the main valley 200 yards west of the Waipori Township. 
This certainly marks the old channel of the Lammerlaw Creek, which took this course 
before the drainage of the main valley, as the result of the thrust-movement, was 
blocked. After the gravels had accumulated in the temporary lake the stream flowed 
over them along its present course, which was incised deeply into the schist as the 
removal of the gravel was gradually effected. This deep lead soon attains a depth 
of 70 ft. below the floor of the main valley, and turns down-stream. 

Origin and Age oj Waipori Gravels. 

McKay reasonably points out that the whole watershed of the Waipori River is 
formed of schist which is very rich in quartz lenticles, so that fragments of quartz cover 
much of the ground. Such a surface would readily supply the material of the quartz 
gravels which constitute the infilling of the Waipori basin. The deposition of the gravel 
began when the earth -movements along the thrust-plane had become sufficiently great 
to dam the Waipori valley. The Waipori River flowed over the edge of the great 
upthrust barrier, and speedily began to cut its way back. The waterfall, which at 
first was situated near Berwick on the outer edge or scarp of the upthrust block, has 
now degenerated into a cascade, and has receded seven miles, notwithstanding that 
for some considerable time the river was poorly suppUed with transported matter 
for erosion, since for a long period all such matter accumulated in the lake that 
was formed, and on being filled up became the Waipori Flat. It is hardly possible 
to estimate the lapse of time required for such a recession of seven miles, but it 
is reasonable to place the thrust-movement that preceded it as far back as the 
Pleistocene, and thus ascribe the formation of the gravels of the Waipori Flat to the 
Pleistocene period. 

Economic Geology of Waipori Gravels. 

The Waipori Flat was first worked by the diggers towards the close of 1861, 
and its superficial portion proved very rich, and for a short time supported a 
large mining population. The original claims were very small, and in a few years 
most of the superficial gold had been recovered. The era of the individual European 
miner was followed by that of the Chinaman, who rewashed the gravels and extracted 
still more gold. Afterwards the dredges came, and as they worked to a greater depth 
than the digger they obtained still more gold. Sluicing claims to the number of four 
are now at work in the Waipori and Lammerlaw streams, operating partly on the 
terraces and partly on the deep lead. 

The superficial layers were of greater richness than the rest, because the Waipori 
River has eroded the upper part of its gorge nearly 200 ft., and thus over the whole 
of the flat a thickness of some 200 ft. of quartz gravels has been removed by the 



67 

action of the river. The gold contained in this gravel was not removed, but was 
concentrated in the surface layers of the remaining gravels. The work of the dredges 
and the hydraulic sluicing in the deep leads, however, have shown clearly that the rest 
of the gravel is auriferous to a sufficient extent to pay for hydraulicking-work. Thus 
an immense amount of auriferous gravel still awaits treatment in the Waipori 
Flat. 

If sufficient water-power can be obtained to allow of sluicing and elevating being 
undertaken on an extensive and comprehensive scale an immense amount of gold 
will yet be obtained. At present the water-supply available is Umited, but if the 
water of the Deep Stream were brought in a much greater amount of the material 
could be treated. 

A very large quantity of gold has already been saved in the Waipori field. At 
one time it is said that some four thousand miners were doing well. At a later period 
as many ts fifteen dredges were at work, and getting satisfactory results. It has. 
however, been found impossible to prepare a table showing the quantities recovered 
at different periods, or even to find out the total quantity of gold that Waipori has 
yielded during the fifty-six years that have elapsed since the first diggers appeared. 

It is probably true that the amount of gold that still remains is greater than the 
amount that has been obtained. Unfortunately, the gold that remains will not be 
easily got. It is probable that, with the exception of patches in the deep leads, no 
portion of the remaining auriferous gravels will be so rich as the original surface of 
concentrated material. The untreated gravels, though of immense bulk, are at a con- 
siderable depth, and require expensive plant and considerable power for their successful 
treatment. 

Waipori has been the home of several important inventions and of the application 
of novel methods in gold-saving. It was here that elevators were first used in New 
Zealand, soon after their introduction in California. The automatic nozzle operator 
and the hydraulic dredge are the inventions of Mr. W. O'Brien, and they have proved 
very successful where conditions are suited for their use. 

Mitchell's Flat. 

This is situated about a mile and a half south of Waipori, near the head of 
Pioneer Creek. The gold-bearing gravels of the flat are of the same general nature 
as those of Waipori Flat, and their formation is due to the same general set of 
causes. They form merely a portion of a most extensive deposit that reaches almost 
to the foot of the Waitahuna Heights. A deep ead which slopes rapidly to the 
east has been uncovered, and has proved extremely rich. The present water-supply 
is not sufficient to allow of rapid working, but a larger supply will soon be available. 
The gold obtained here is fine, but, like the rest of the Waipori gold, it is not much 
water-worn. The ground that is at present being worked is not deep, but it 
becomes deeper rather rapidly towards the east. No information is available as to 
the depth of the vast areas of gravel which extend for three miles in the direction 
of the Waitahuna Heights. If water were available it is probable that the whole of 
this great area could be sluiced, and would yield satisfactory returns. 

Verter Burn. 

This stream, which flows from north-east to south-west, is generally known by 
the name of Post Office Creek. It is a tributary of the Waipori, which it joins directly 
above the gorge corroded by this river through the upthru.st mass of schist constituting 

5*^Tuapeka. 



68 

the Maungatua Ridge. The lower portion of this valley has been worked in the same 
way as the Waipori Flat — first by European miners, afterwards by Chinese, then 
by dredges, and now by hydraulic elevating and sluicing which is following up the 
deep lead that the dredge could not bottom. Good returns are being obtained. 

Deposits of quartz gravels some 150 ft. in thickness occur for six miles up the valley 
of the stream. These deposits are on the south-east bank, and are often at a consider- 
able distance from the stream, which now flows in a deep schist gorge, and is thus 
responding to the late earth-movements which have initiated a new cycle of erosion. 
In the quartz gravels the old stream-channel or deep lead has been followed for a 
considerable part of the six miles. This old channel when excavated is shown to be a 
schist gorge up to 60 ft. in depth, with steep sides, and with potholes and other 
evidences of energetic stream erosion on its floor. At a distance of some five miles from 
the jimction with the Waipori the old channel or deep lead, still filled with quartz 
gravels, is found on the summits of some of the spurs, still constituting a nearly 
continuous line. About five and a half miles distant from the Waipori the deep 
lead forks at a point locally called the " Split." From this point one branch can be 
traced first in a northerly direction, but it afterwards bends romid to the west ; it 
can be traced for a total distance of five miles. It extends into the watershed of 
the Lee Stream for the last three miles of its course. 




v//- MAP 

Showing Deep Lead in Valley of 
POST OFFICE CREEK 
WAIPORI S.D. 

Scale 
CHAINS ao 40 I 

. ■ I I 

Deep Lead Quartz Gravels - Recent \''-y^///i 
Mica Schist Mesoioic I I 



This deep lead e\'idently marks an important channel of drainage of the period 
pre\'ious to the great earth-thrust which was the cause of the formation of the lake, 
followed by the gravel plain of the Waipori Flat. The fact that this old channel, filled 
with fine quartz gravel throughout its length, went to a height of 500 ft. above the 
Waipori Flat proves that it was filled with its present contents while the ground 
over which the stream then flowed was still only gently sloping, for the blocking of 
the Waipori drainage stopped the flow of water in this old tributary throughout its 



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69 

length, and allowed its channel to be filled up with fine material. The present elevation 
of the old channel proves either that the intensity of the earth-thrust was greater 
in the northern than in the southern portion of its basin, or that the thrust was 
directed from the south-west. Since the eastern scarp of Maungatua, which is regarded 
as the main evidence of this thrust-movement, is directed north-east to south-west 
the latter explanation appears unsatisfactory. On the other hand, the fact that the 
Maungatua scarp rises gradually from its south-west end indicates that the former 
explanation is the more likely one, and that this great thrust produced a less effect 
near the Waipori Gorge than farther north. The greater elevation of this old channel 
in its northern than in its southern portion indicates that this differential movement of 
the thrust took place subsequently to the movement that caused the blocking of the 
Waipori, and the consequent stuffing-up of its tributary channel with fine - quartz 
gravel. 

Some indication of the time that has elapsed since the initiation of this later 
thrust-movement is to be found in the depth to which the gorge of the Verter Burn 
has been corroded. This appears to have a maximum of 200 ft. in hard schist rock. 
The stream has not a large body of water, its grade is not particularly steep, and 
erosion would be slow. It seems reasonable to suppose that it implies such a lapse 
of time as to justify the classification of the quartz gravels (which fill the old channel, 
and accumulated before this corrosion began) in the Pleistocene period. 

It has already been stated that much gold has been obtained in the Verter Burn, 
or Post OfB.ce Creek. The extent of the old workings is considerable. All the patches 
of the deep lead at present cutting across spurs in the more distant part of the field 
were timnelled, and the rich portions of the gravels were extracted. At the present 
time there are four sluicing claim.s at work. Much of the gold is very fiaie, though 
on the bottom of the deep lead it is rather coarser. A vast amount of gravel remains 
to be treated, but the supply of water is even more inadequate here than elsewhere 
in the district. Throughout quite a large portion of the valley auriferous-quartz 
gravels form cliffs nearly 100 ft. high. The greater part of the richer portion has 
already been treated, and for the successful working of much of the remaining gravel 
a good supply of water under considerable pressure is necessary. 



Gravel Terraces of Molyneux and Tuapeka Rivers. 

Molyneux River Terraces. 

The terraces formed by the Molyneux River are comparatively small, for over the 
greater part of the district the elevation has been so rapid that the Molyneux has been 
corroding its bed for a great length of time, and no lateral action with the associated 
formation of terraces has taken place. They have considerable importance at the junction 
with the Tuapeka, for in this place they are more extensive and are auriferous. This 
fact, however, is due to the Tuapeka River, which has transported to the junction 
some of the detritus derived from the denudation of the auriferous cement of the 
Bluespur and Wetherstones areas. The auriferous terrace gravels of this locality are at 
present being worked on a limited scale. 

Tuapeka River Terraces. 

Some four miles above its junction with the Molyneux River, terraces begin 

to appear on the banks of the Tuapeka. At first some of these are 100 ft. above 

the bed of the stream, but their height gradually decreases, until near Lawrence the 

average height is about 20 ft. These terraces have an irregular rock floor on which 



70 

gravel rests of a thickness varying from 5 ft. to 20 ft. The formation of these terraces 
was evidently due to a period of tranquility in the earth-movements to which the 
elevation of the district was due, and the accumulation of gravels on the rock surface 
may even point to a temporary movement of depression. This is further indicated 
by the occurrence of an old gravel-filled channel of the Tuapeka River below its 
present level, above Evans Flat near Gray's Gully.* The terrace gravels were often 
quite rich, and practically all of them were hand-washed by the early diggers. In 
later times a few of them have been sluiced, and probably a good deal more work 
will still be done, for much of the gold contained in them yet remains to be 
recovered. 

* Morgan, P. G. : " The Lawrence- Waipori District." N.Z.G.S. Ann. Rep. No. 8, in C.-2 (Mines Report), 
1913, p. 155 



71 



CHAPTER VIII. 



RECENT DEPOSITS. 



Valley Gravels 
Distribution 
Tuapeka Flat 
Havelock (or Waitahuna) Flat 



Page 
71 
71 
71 
71 



Valley Gra^vels — continued- 
Distribution — continued. 
German Creek Flat 
Surface Clays 



Page 



72 
72 



Valley Gravels. 

Distributimi. 

Recent stream - gravels are by no means extensive in the Tuapeka district, and 
where they occur are generally not more than 15 ft. in thickness. They have their 
greatest extent on the Tuapeka and Waitahuna flats, where they consist of schist 
pebbles, which are of relatively small size. 

Tuapeka Flat. — The Tuapeka Flat may be considered as extending to Evans Flat and 
up Munro's Gully as well as Gabriel's Gully. These were the deposits in which gold 
was first found in this district, and very rich returns were obtained from the small 
claims which were at first allowed. It was speedily proved that nearly all the gold 
in these gravels was derived from the auriferous cement in the Bluespur and the 
Wetherstones areas, for where the gravels were tested above the outcrop of the cement 
they were nearly destitute of gold. 

Other alluvial gravels occur in small basins in various localities, such as Boulgers 
and Bungtown, on the road between Waipori and Lawrence. These gravels are covered 
with a growth of swampy vegetation, and but little can now be seen of them. A 
certain amount of work has been done in both of these areas, and some rich patches 
have been found. It is notable that these gravels are locally derived, and that the 
small streams which supply them were auriferous to their sources ; yet no auriferous 
lodes have been found in their basins. This fact is cited by McKay as evidence that 
the alluvial gold of the district is in large part derived from quartz lenticles in the 
schist, and not from distinct quartz veins. This opinion is advocated elsewhere in this 
bulletin (see pp. 15, 42). Other small alluvial areas occur here and there, but are of 
no geological importance ; one of these is situated at the crossing of the Havelock- 
Waipori Road, over the Waitahuna north branch. It consists entirely of quartz gravels, 
which contain a small quantity of gold, though when they were sluiced the results were 
poor. 

Havelock (or Waitahuna) Flat. — The Havelock (or Waitahuna) Flat is of the same 
nature as the Tuapeka and Wetherstones flats. The gold contained in its gravels was 
clearly derived from the cement of Waitahuna Gully. It is, however, notable that gold 
does not occur in the gorge, fourteen miles long, between the Havelock Flat and the 
Molyneux River. This may be explained by the supposition that the gold was all 
deposited in the relatively sluggish water of the river throughout the distance where 
it passes over the flat. The flat appears to be faulted down, but no actual proof 
of this could be found. Its gravels have been worked in the same way as those 
of the Tuapeka Flat, and in the same succession- — European diggers, Chinese, dredges, 
hydraulicking ; and the latter is still being continued with success. The hydraulicking 
is carried on to a depth of 20 ft., where a false bottom of quartz-grits is found. This 
false bottom, with an interbedded seam of lignite, is well seen near the Waitahuna 
Railway-station . 



72 

German Creek Flat.- — This is a small patch of auriferous ground one mile north- 
east of Forsyth. It is a low-lying flat, which the creek enters by a gorge and leaves 
through a gorge. The flat is covered with gravel containing a number of " chinaman " 
boulders. Its proximity to Forsyth suggests that the gold, which is very fine, is 
derived from a portion of the Forsyth cement which at one time extended to the 
watershed of this stream. The presence of " chinaman " boulders, which are also found 
on the Forsyth cement, supports this view. The amount of gold obtained from 
German Flat was small. 

Surface Clays. 

All the flatter ground of the south-western part of the Tuapeka district, and the 
sides of spurs that have a northerly aspect, are covered with a considerable thickness of 
clay. Many sections show clearly that this clay has been formed in situ by the decom- 
position of the altered greywacke of which the country is mainly formed. In the 
districts of mica-schist, however, angular quartz pebbles form an important constituent 
of the soil. Sections show that there is a general tendency for these to be smaller 
in size near the surface than at a greater depth. The quartz is in reality associated 
with a good deal of albite, and the gradual decomposition of this mineral and the 
solvent action of the sodium carbonate thus liberated in all probability account for this 
reduction in size. 

These clays are often of considerable thickness, and are quite suitable for brick- 
making and other work of a similar nature. They have been used for this purpose 
to some extent, but the local demand for bricks is not large, and equaUy suitable 
material for brickmaking is found close to the larger centres of population. 



■ turomi,nny Biill.lui If? IS Ti:<tlJil,rr District , Cciitml Otncin mi:/ EnitO-ni (Jliicii,Divir:ious. OtiyloLurid Dialri 




73 



INDEX. 



ABC lode, 39. 

Acid igneous rocks, absent from district, 43. 

Adams Flat — 

" Cement " area at, 48, 56-57. 

Cement workings at, 14, 60. 

Faulting at, 49. 

Quartz-grits at, 61. 

Sketch-map of, 56. 
Agriculture, 7, 11, 12. 
Albite, 31, 33, 71. 

Alexandra, stibnite in schist at, 43. 
Allanton, conglomerates near, 57. 
Alluvial-gold deposits, 48-71. 

Association of, with metamorphic rocks, 42. 

Discovery of, working of, &c., 13-15. 

Enrichment of, near lodes, 43. 

Fulton's Creek, 40. 

Gabriel's Gully, 41. 

Gray's Gully, 42. 

In river-flats, 7. 

Not connected with lodes, 42. 

Nuggety Gully, 39. 

Tokomairiro River, 26. 

Tuapeka River. 25. 
Alluvial mining, 14, 15, 59, 66, 67, 69, 70, 71. 
Amphibia, 4. 
Analyses of — 

Greywacke and schist, 36. 

Nepheline-bearing rocks, 64. 
Andesine, 29. 
Anticlinal of New Zealand turning south-east in 

Otago, 19, 35. 
Antimony, 9, 15-16, 37, 43. 
Antimony lode, Lamraerlaw Mountains, 43. 
Ants, 4. 
Arahura Series, comparison of, with Tuapeka Series, 

27, 29, 36. 
Aralia Tasmani, 58, 59, 62. 
Area described, 1, 2. 
Arsenopyrite, 38. 
Assays of — 

Lode material, 15, 38, 39, 40, 41, 42, 44. 

Mullock, Canton lode, 38. 

Quartz lenticles in schist, 15, 42. 

Tailings, 38. 
Tungsten -ore, 40, 45. 
Assistance, 1. 
Augite, 29, 30. 

Auriferous quartz, &c. {see Gold). 
Automatic-nozzle operator, 67. 
AveUana, 62. 



B. 

Balclutha — 

Foliation-planes not coincident with stratifi- 
cation-planes, 18, 35. 

Greywacke near, unaltered, 28, 29, 36 

Schists near, 27. 
Baldwin, Captain, 13. 
Ballarat Gorge, 65. 
Barewood, 9, 18. 



Basalt, Waitahuna Heights, 64. 

Basanite, 19, 63-64. 

Basins in stream -vallej's, 25, 26, 65, 66, 68 

Bates, 1). C, 8. 

Battery Creek, 39. 

Beal (gold-miner), 37 

Beal, L. ()., 2. 

Beaumont, alluvial gold at, 12. 

Beaumont, forest near, 5. 

Beech-trees, 5. 

Bees, 4. 

Beetles, 4. 

Bell, J. M., 36. 

Bella lode, 37, 39. 

Bell-bird, 4. 

Berwick, 66. 

Big Hill, 24, 61. 

Birch -trees, 5. 

Birds, 3-4. 

Black Peter (Edward Peters), 12. 

Blackbird, 4. 

Block mountains, 26. 

Blowflies, 4. 

Blue Mountains, 22. 

Bluespur — 

Auriferous schist from, 34. 

Fault at, 49, 50, 51, 55. 

Origin of name, 14. 

Schist from, 34. 

Workings, plan of, 51. 
Bluespur " cement " or conglomerate — 

Account of, 48-60. 

Discovery of, &c., 13. 

Hutton's account of, 2. 

Papers on, 9. 

Relation to quartz-grits, 61-62. 

Supposed source of gold of, 41. 

Iransported gold from, 69, 70. 
Bluespur Consolidated Gold-mining Company, 59. 
Bogs, 22. 

Bottleman, H. A. (quartz-miner), 40, 
Boulgers, auriferous gravel at, 71. 
Bowler's Run, discovery of gold at, 12. 
Bracken, 6. 

Brickmaking, cla}- suitable for, 72. 
Brookes (prospector), 13. 
Broom, 6. 

Bungtown, auriferous gravel at, 71. 
Bungtown Stream, 25. 
Burnt Creek lode, 42. 
Burrell (miner), 37. 
Burtenshaw (scheelite-miner), 45. 
Butterflies, 4. 

c. 

Cabbage-tree, 6. 

Calcite, 30. 

California, tungsten-ore of, 46. 

Cahfornian Cretaceous fossils, 63. 

Cambrian age of schists, supposed, 28, 35. 

Canada lode, 41, 42, 45, 63. 

Basanite near, 64. 
Canton lode, 37, 38-39. 



74 



Carboniferous age of greywacke, supposed, 17, 28. 

Carew, E. H. (Warden), 8, 9, 15, 41. 

Cargill, J. (miner), 13. 

Cassinia, 5. 

Cats, wild, 3. 

" Cement " — 

Account of, 48-60. 

Age of, 18, 58. 

Agriculturally considered, 7. 

Areas, 13, 48-60. 

" Chinamen "' associated with, 61 

Crushing, 14, 59. 

Economic geology of, 59-60. 

Glacial origin of, suggested, 2, 18, 49, 50, 52, 58. 

Methods of mining, 14, 15, 66, 67, 69, 70, 71. 

Methods of treating, 59. 

Origin of, 2, 18, 50, 58. 

Origin of name, 52. 

Palaeontologj' of, 58. 

Relation to quartz-grits of, 11. 
Cemetery lode, 39. 
Cereals, 6, 12. 

Cervantite, Stony Creek, 43. 
Chalcopyrite, Waitahuna, 44. 
Charley's GuUy, 39. 

Chemical composition of greywacke and schist, 36. 
Chemical composition of nepheline-bearing rocks, 

64. 
Chemical erosion of quartz grains, 30, 33. 
Chemical treatment required for ore from Bella 

lode, 39. 
" Chinamen " (sarsen-stones), 5, 54, 55, 56, 57, 61, 

65, 72. 
Chinese miners, 14, 38, 66, 68, 71. 
Chlorite, chlorite schist, &c., 28, 31, 33. 
Cicada, 4. 

Cinnabar, 16, 44—45. 
Clarendon nephelinite, 64. 
Clarke's Hill, 41. 
Claj's, residual, 19 72. 
Climate, 8. 

Climatic influence in erosion, 24. 
Clutha River, 12, 17, 24, 30. 
Coal, brown, Lawrence, 9. 
Coal in quartz-grits, 18. 

Coghill's Hill, auriferous quartz-grit of, 61, 63. 
Conditions of deposition of Waitahuna Series, 64. 
Conformity, Wanaka-Kakanui formations, 17, 29. 
Conglomerate (see " Cement " ; Quartz-grits). 
Copper-ore, &c., 9, 16, 37, 44. 

Origin of, 44. 

Waipori lode, 9. 

Waitahuna lode, 44. 
Coriaria (tutu), 5. 
Cosmopohtan lode, 37, 40. 
Cossmann, Maurice, 62, 63 (footnote). 
Cotton, R. J., 38, 42, 45. 
Cox, S. H., 2, 9, 17, 27, 28, 50, 58, 61, 62. 
Cox's lode, 37, 39-40. 
Crescent Claim, 24. 
Cretaceous age of " cement," 18- 
Cretaceous beds. Shag Point, 58, 62. 
Cretaceous fossils, 58, 63. 
Cretaceous history of Tuapeka district, 20. 
Culture, 11-16. 



D. 

Danthonia grass, 6. 

Darton, H. L., 52, 58. 

Davy and Bowler's Run, early discovery of gold 

at, 12. 
Deep lead, map of, 68. 
Deep lead, Waipori, 65, 66, 68. 



Deep Stream, minerals and veins of, &c., 40, 44, 45. 

Deer, 3. 

De Launay, 9. 

Devil's Creek lode, 40. 

Devil's Creek scheelite, 45. 

Devonian age of greywacke formation, supposed, 

17, 28. 
Dickerson, R. E., 63 (footnote). 
Dogstail-grass, 6. 
Dotterel, 3. 
Dragon -flv, 4. 

Dredging," gold, 14, 57, 66, 67, 68, 71. 
Duck, 3. 

Dunedin, electric power for, 26, 65. 
Dunedin phonolite used for roads, 11. 



E. 



Eaton (miner), 44. 
Economic geology of the — 

" Cement," 59. 

Quartz-grits, 63. 

Tuapeka Series, 37. 

Waipori gravels, 66. 
Eels, 4. 

Electric power generated at Waipori Gorge, 26, 65 
Elevation of the land — 

Periods of, 20. 

Tertiary, 22, 24. 
Elevators, hydraulic, 59, 67. 
Endeavour Inlet, stibnite in schist at, 43. 
Eocene — 

Age of " cement," 18, 58-59, 62-63. 

Fossils in quartz -grits, 63. 

History in Tuapeka district, 20. 
Epidote, 30, 31, 32, 33. 
Ettingshausen, C. von, 58, 62. 
Euthriof-usus, 63. 
Evans Flat, 25, 61, 70, 71. 

Gravels of, 71. 

Quartz-grits of, 61. 
Eye-structure in schist, 32. 



F. 



Fantail, 4. 

Farming in Tuapeka district, 11, 12. 
Faults and faulting, 9, 20, 22, 23, 24, 26, 49, 50, 51, 
53, 54, 55, 57, 61, 65, 66, 68. 

Effect on streams, 26, 65, 66, 68. 

Late Tertiary, 20, 22, 24, 64. 

Map showing, 23. 
Fauna, 2. 
Ferns, 6. 
Fescue, 6. 
Fiddler's Creek, 40. 
Finches, 4. 

Finlayson, A. M., 10, 15, 36, 39, 43, 46. 
Fires, grass and forest, 5, 6, 22. 
Fishes, 4. 

" Flax " (Phormium), 6. 
Flies, 4. 

Flood-plains, 7. 
Flora, 5. 
Folding — 

Of Tuapeka Series, 34-35. 

Periods and directions of, 19-20. 

Post-Triassic, 18. 
Foliation -planes coincident with bedding -planes, 

18, 34. 



75 



Foliation-planes exceptionally not coincident, 18, 

35. 
Forests, 5. 
Forsyth — 

" Cement " at, 48, 54-55, 60, 72. 

Fault at, 49, 55. 

Quartz-grits at, 61. 
Fossil leaves, wood, &c., 51, 52, 54, 58-59, 62, 63. 
Fossils, 17, 18, 20, 35, 51, 52, 54, 58-59, 62, 63. 
Fossils, scarcity of, 17, 18. 
Frogs, 4. 

Frost-action, influence on shape of hills, 24. 
Fruitgrowing, 8. 
Fulton's Creek, 40. 
Fulton's lode, 37, 40. 



G. 



Gabriel's GuUy — 

" Cement " of, 14, 48, 54, 55, 59. 

Discovery of gold at, &c., 13. 

Fault gutter at, 50-51. 

Forest at, 5. 

Lode, 9, 41. 

Reports on, 9. 

Sluicing Company, 60. 
Gare (miner), 39. 
Garvie, Alexander (surveyor), 12. 
General information, 1-8. 
Geological history of New Zealand, reference to, 2, 

10. 
Geological history of Tuapeka district, 17-21. 
Geological surveys, previous, 2, 17, 27, 28. 
Geology, structural, 17, 18, 19, 20, 34-35. 
German Creek Flat, auriferous gravels at, 72. 
Oilbertia, 62. 
Glacial origin of " cement," supposed, 2, 18, 49, 

50, 52, 58. 
Glacial origin of Taieri " moraine," supposed, 

57-58. 
Glenore — 

" Cement " at, 48, 57, 60. 

Faulting at, 49, 57. 

Greywacke at, slightly metamorphosed, 20, 
36. 

Phyllite at, 29. 

Quartz-grits at, 61. 

Sketch-map of, 56. 
Gold, alluvial (see also " Cement," Quartz-grits) — 

Deposition of, 15. 

Deposits, reports concerning, 8-10. 

Discovery of, 8, 12, 13. 

In " cement " {see " Cement "). 

In greywacke, 42, 43. 

In lodes, 15, 37-43, &c. 

In Recent gravel, 71, 72. 

In schist, 15, 42, 43. 

In veins of pneumatolytic origin, 46. 

In Waitahuna copper lode, 44. 

Origin of, 15, 37, 42, 43, 71. 

RecrystaUized, 42, 43. 

Relation of, to igneous rocks, 43. 

Saving, 14. 
Golden Crescent Claim, 53, 54, 60. 
Golden Padlock Claim, 44. 
Gold-mining industry, 12-15, &c. 
Gold-mining methods, 14, 15, 59, 66, 67, 69, 71. 
Gorse, 6. 
Gradation from greywacke to schist, 17, 28, 

29-34. 
Granite, hypothetical subjacent magma, 43, 46, 

47. 
Granite, local name for quartz-grits, 60. 
Grasses, 6, 7, 12. 



Grasshoppers, 4. 

Gravel terraces of Molyneux and Tuapeka rivers, 

69-70. 
Gravels (see also Quartz-grits, &c.) — 

Waipori quartz, 66-69. 

VaUey, 71-72. 
Gray's Gully, 42, 69. 
Greensand formation, 19. 
Gregory, H. E., 58. 
Gregory, J. W., 19. 
Greywacke — 

Analyses of, 36. 

Auriferous, 42, 43. 

Petrography of, 29-34. 

Relation of, to schist, 17, 18, 28, 29-34. 

Tungsten -bearing, 47. 
Grits (see Quartz-grits, &c.). 
Gypsum, secondary, 43. 



H. 

Hardy (miner), 13. 

Harrier-hawk, 3. 

Havelock or Waitahuna, 11, 25. 

Auriferous gravels at, 71. 

Cement area at, 55. 

Greywacke-schist gradation at, 28, 29. 

Quartz-grits at, 61. 
Hawk, 3, 4. 

Hector, J., 2, 9, 10, 18, 27, 28, 34. 
Henley or Taieri " moraine," 67, 58. 
Heteroterma, 63. 
Hill (miner), 37. 

History of gold-discovery, 12-13. 
Button, F. W., 2, 9, 10, 15, 17, 18, 19, 28, 29, 34, 

35, 36, 38, 41, 44, 49, 52, 58. 
Hyde, G. E., 1, 64. 
Hyde, volcanic rocks near, 43. 
Hydrauhc dredge, 67. 
Hydraulic mining, 14, 15, 59, 66, 67, 69, 71. 



Igneous magma, hypothetical subjacent, 43, 46. 
Igneous rocks, 19, 43, 63-64. 

Rocks, effect on gold-content in schist {see also 
Basanite ; NepheUnite), 43. 
Industries, 12-16. 
Inhabitants, 11. 
Insects, 4. 
Introduction, 1. 
Isolation of New Zealand, effect on fauna, 2, 



Jackson, Howard, 9. 
Jenkins, J. (miner), 13. 
Johnson, J. T. (miner), 65. 
Johnson's claim, 65. 
Jurassic history of Tuapeka district, 20. 
Jura Trias rocks, &c. (see also Tuapeka Series), 
17, 21, 35-36. 



K. 

Kaka, 3. 

Kaihiku fossiUferous beds, 18, 35, 36. 

Kaikoura System, Hutton, 17, 28. 

Kaitangata, 26. 

Kakanui System, Hutton, 17, 28, 29. 

Knight (miner), 39. 



76 



L, 



Lakes, old basins formed by faulting, &c., 26, 65, 

66, 68. 
Lammerlaw Creek — 

Minerals and lodes of, &c., 40, 42, 44, 45, 47. 

Old channel of, 66. 
Lammerlaw Mountains, 2, 13, 18, 22, 24, &c. 

Account of, 22. 

Alluvial diggings of, 14-15. 

Antimony lode of, 43. 

Auriferous lodes of, 40-41. 

Drainage of, 25. 

Peneplain remnants of, 22, 24. 

Scheelite of, 45. 

Supposed Cambrian rocks of, 28. 
Leaves, fossil — 

In " cements," 51-52, 54, 58. 

In quartz-grits, 62. 
Lee Stream, deep lead of, 68. 
Leith, C. K., 10, 36. 
Lignite — 

In " cement," Wetherstones, 54. 

In quartz-grits, 61. 

In Recent gravels, 71. 
Limestone, 19. 
Lindgr n, W., 10. 
Lindsay, P. (miner), 13. 
Lindsay, W. L., 9. 
Linnet, 4. 
Literature, 8-10. 

Lithologic differentiation of formations, 17, 18. 
Lizard, 4. 
Lodes — 

Antimony, Lammerlaw Mountains, 43. 

Auriferous, 15, 37-43. 

Auriferous, not adequate to supply the allu- 
vial gold, 42. 

Cinnabar, Waitahuna, 44-45. 

Copper, Waitahuna, 9, 44. 
Long (miner), 38. 
Long Gully, 39. 
Loughnan, R. A., 10. 
Lycopodium, 6. 



M. 



McKay, Alexander, 9, 15, 17, 18, 27, 34, 50, 51, 52, 

56, 58, 61, 62, 71. 
Macrae's — 

Mica-schist at, 36. 

Scheelite at, 46. 

Volcanic rocks near, 43 
Maestrichtian age of quartz-grits, 18, 62. 
Magmas, hypothetical, 43, 46. 
Magmatic origin of gold and scheehte, 43, 46. 
Magnetite, 28, 29, 30. 
Maitai System, 17, 28. 
Mammals, 2. 
Manganese, 37, 39. 

Manuherikia River, gold discovery near, 12. 
Manuka, 5. 

Manuka Gorge, 28, 31. 
Manuka HiU, 61, 63. 
Maori expansion. Cox's lode, 39. 
MarshaU, P., 10, 17, 19, 28, 63, 64. 
Martinez fossils (California), 63. 
Maud expansion. Cox's lode, 39. 
Maungatua, Mount — 

Gorge near, 25. 

Portion of peneplain formed by, 24. 

Scarp, 22. 

Thrust, 65, 67, 68. 



Mayfly, 4. 

Mead, W. J., 10. 

Means of communication, 11-12. 

Mercury, 16, 37, 44-45. 

Mercury-ore, 16, 37, 44-45. 

Mesozoic rocks, &c. {see also Cretaceous ; Jurassic ; 

Triassic ; Tuapeka Series), 28, 35-36. 
Metamorphism — 

As a ba.sis of differentiation of formations, 17, 
27. 

Leith's theory of, 36. 

Progressive, greywacke to schist, 29-34. 

Relation to distribution of gold, 42. 

Relation to folding, 18. 

Works on, 10. 
Meteorology, 8. 

Method of conducting work, 2. 
Methods of mining, 14, 15, 59, 66, 67, 69, 70, 71. 
Mica-schist {see also Schist) — 

Analyses of, 36. 

SoU formed from, 7. 
Milburn, 19, 26, 57. 
MUton, 2, 24, 30, 57. 
Mining — 

AUuvial, 14, 66, 67, 69, 71. 

Antimony, 43. 

Cinnabar, 44-^5. 

Copper, 44. 

Industry, 12-16. 

Quartz, 15, 37-42. 

Scheelite, 45^7. 
Minnow, 4. 

Miocene fossils among the Wangaloa fossils, 63. 
MitcheU's Flat, 38, 67. 
Mitchell's Point, near Kaitangata, 62. 
Molyneux River, 2, 21, 22, 24-25. 

Flood-plain of, 7. 

Forest near, 5. 

Gravels of, 19. 

Structure near, 35. 
" Moraine," Taieri, 57-58. 
Morgan, P. G., 10, 27, 36. 
Mosgiel, 26. 
Moths, 4. 

Mounds containing wood and charcoal, 5. 
Mount Misery, 57, 62. 
Mount Stuart, 26, 30. 
Mountain systems, 19, 20. 
Mountains and hills, 21-24. 
Mouse, 3. 

Mullock, Canton lode, assay of, 38. 
Mungo River greywacke, 36. 
Munro, 12. 

Munro's farm, quartz-grits, 61. 
Munro's Gully — 

" Cement" of, 12, 13, 14, 48, 59. 

Fault near, 50, 51. 

Forest or, 5. 

Gravels of, 71. 
Muscovite, 29, 30, 33. 



N. 

" Nardoo " berry, 3. 
Nardoo Creek — 

Cinnabar of, 44. 

Gold of, 42. 

Forest of, 5. 

Scheelite of, 45, 47. 
Nepheline-basanite, 63-64. 
Nephelinite, 63, 64. 
Nugget Point — 

Feldspar porphyrite at, 46. 

Stratigraphic relation with Balclutha, 36. 
Nuggety Gully lode, 37, 38-39. 



77 



0. 



O'Brien, W., inventor of mining apparatus, 67. 

Ocean View lode, 41. 

OUgoclase-ancle.sine, 31. 

O.P.Q. lode, 9, 37-38, 42, 4.5. 

Ordovician age of Tuapeka Series, supposed, 28 

Origin of gold, 15, 37, 42, 43, 71. 

Origin of scheelite, 46. 

Orthoptera, 4. 

Olujo Prorinrinl Gazette, 8. 

Otakaia, report on coal prospects at, 9. 

Oyster-catcher, 4. 



Paddy's Point, 54, 60. 

Palaeocene fossil, 62. 

Paleontology of the " cement," 58-59. 

Palaeontology of the quartz-grits, 63. 

Park, J., 10, 15, 18, 19, 28, 50, 58, 62. 

Parrakeet, 3. 

Pastoral industry, 12. 

Peat, 15, 22. 

Peneplain, elevated and dissected, 20, 24. 

Peri.isolax (Senonian fossil), 63. 

Permian fossils, Kaihiku, 18. 

Peters, Edward (prospector), 12. 

Petrography of nephehne-basanite, 63-64. 

Petrography of Tuapeka Series, 28-34. 

Phonolite, from Dunedin, used on roads, II. 

Phormium, 6. 

PhylHte embedded in greywacke, 28. 

Phyllite, Glenore, 29. 

Physiographic indications of faulting, 49. 

Physiography, 21-26. 

Pigeon, 4. 

Pigs, wild, 4. 

Pioneer Creek — 

Cinnabar in, 44. 

Oravels of, 65, 67. 
Pleistocene deposits, 65-70. 

Suppo.sed, 18, 50. 
Pleistocene hi.story of Tuapeka district, 20. 
Plutonic rocks, hypothetical, 43, 46, 47. 
Plutonic rocks near Gore, 46. 
Poa grass, 6. 
Ponds, 15, 22. 
Population, 11. 

Porphyrite at Nugget Point, 46. 
Porphyroid appearance of metamorphosed grey- 
wacke, 31, 32. 
Porter (miner), 37. 
Post Office Creek (Verter Burn), 2, 25. 

Deep lead, map of, 68. 

Gravels, 65, 67- . U. 
Previous geological work, 2, 8-10, 27-28. 
Prospecting, early, 12-14. 
Prospecting necessary in irregular ore-bodies, 37-38, 

40. 
Pugnellus, 63. 
Pukeko, 3. 

Pyke, Vincent (Warden), 8, 12, 41. 
Pyrite — 

In " cement," 52, 54. 

In O.P.Q. lode, 38. 

In Waitahuna copper lode, 44. 



Q. 



Quartz crystals, chemical erosion of, 30, 33. 
Quartz gravels, 6.5-67. 
Quartz-grits, 60-63. 
Quartz-grits soils, 6, 7, 8. 



Quartz laminations in schist, auriferous, 15, 42, 

71. 
Quartz lodes (see Lodes). 
Quartz pebbles, solution of, 72. 
Queen Charlotte Sound, antimony-mine at, 9. 



R. 



Rabbits, 2, 3, 6, 12. 

Railway communication, 11. 

Rainfall, 8. 

Rat, grey, 3. 

Read, Gabriel, 8, 12, 13. 

Recent deposits, 71-72. 

Red-bill, 4. 

Reedy Creek, 25, 44. 

Regatta Point (Tasmania), nephelinite at, 64. 

Reports, previous geological, 2, 8-10, 27-28. 

Reptiles, 4. 

Rhodonite, 39. 

Richardson, Major, 13. 

Rickard. T. A., 9, 15, 18, 34, 38, 50, 58. 

Ritchie (miner), 37. 

Rivers, 24 20. 

Roads, 11. 

Robertson, J. (Mayor of Lawrence), 12. 

Rogers, F. (miner), 40. 

Rowe, W. E., 9. 

Russell, \V. (prospector), 45. 

Rye-grass, 6. 



s. 



Sailor's Gully Company, 60. 

Sandagger, F. (miner), 38, 45. 

Sandagger's lode, 38. 

Sarsen stones (see also " Chinamen "), 5 (footnote). 

Scheelite, 10, 16, 37, 38, 39, 40, 43, 45-47. 

Scheelite, origin of, 45-47. 

Schist (see aUo Tuapeka Series) — 

Age of, 17, 18, 20, 28. 

Analyses, 36. 

Auriferous, 15, 42, 71. 

Gradation of, to greywacke, 17, 28, 29-34. 

Soil derived from, 7. 
" Scrub," 5. 
Seagulls, 3. 

Secondary enrichment of lodes, 43. 
Senonian fossil, 63. 
Sequence of formations, 17. 
Sericite, 31, 33. 

Shag Point beds. Cretaceous aj^e of, 62. 
Shag Point fossil plants, 58-59. 
Silurian age of schist formations, supposed, 17, 28. 
Silver, 40, 44. 
Sluicing, 14, 15, 16, 49, .50, 53, .54, 55, 56, 57, 59 

60, 63, 66, 67, 69, 70, 71. 
Snowberry, 3. 
Soils, 7, 12. 
Sparrow, 4. 
Sparrow-hawk, 3, 4. 
Spurs, character of, 24. 
Stanton, T. W., 62, 63. 
Stewart (miner), 39. 
Stibnite (see also Antimony), 43. 
Stoats, 3. 
Stony Creek — 

Antimony at, 9, 15. 

Fohation-planes not bedding-planes at, 18, 
35. 

Greywacke-schist gradation at, 28, 29, 30. 

Lodes, 40. 



78 



Stratification-planes, 18, 34, 35. 

Stream-valleys, 11, 26. 

Structure, Tuapeka Series, 17, 18, 19, 20, 34-36. 

Suess, E., 19. 

Sulphide ore, copper, 44. 

Sulphides, generally absent from lodes, 43. 

Surveys, previous geological, 2. 

Swarap-hen, 3. 

Syntaxis of mountains in Otago, 19. 



T. 



Table Hill, 41, 61. 

Table of chemical composition of rocks of grey- 

wacke-schist series, 36. 
Table of geological events, 20. 
Table of rainfall, 8. 
Taieri " moraine," 57-58. 
Tailings, assay of, 38. 
Tapanui Mountains, supposed glacial boulders from, 

52. 
Tern, 3. 

Terraces, formation of, 69. 
Tertiary deposits {see Pleistocene, &c.). 
Tertiary elevation, faulting, &c., 20, 24. 
Tertiary geological history, 20. 
Thomson, J. T., 8, 13. 
Thrush, 4. 
Thrusts— 

Effects in stream-valleys, 26. 

Maungatua, 65, 67, 68, 69. 

Milburn, 57. 

Tertiary, 20, 22, 24. 

Tuapeka district, map, 23. 
Waipori, 66. 

Wetherstones, 53. . 

Tilting- movements, 20, 24, 25, 26. 
Timber, 5. 
Toetoe, 6. 
Tokomairiro Plain, 7, 21, 22. 

Basanite near, 19. 

Greywacke-schist gradation near, 28. 
Tokomairiro River, 2, 24 26. 

Alluvial gold, 12, 14. 

" Cement," 57. 

Lodes, 41. 

Relation of quartz-grits to " cement," 62. 
Tomtit, 4. 
Totara, 5. 

Trechmann, C. T., 18, 58. 
Tree-ferns, 6. 
Trias-Jura — 

Age Kaihiku Series, 36. 

Age Maitai System, 21. 

Age Nugget Point beds, 36. 

Age Tuapeka Series, 35-36. 
Triassic — 

Age of Kaihiku fossils, 28. 

Age of Maitai System, 17, 28. 

History of Tuapeka district, 20. 
Trout, 4. 
Tuapeka District — 

Map showing faults of, &c., 23. 

Previous reports on, 8-10, 27-28. 
Tuapeka River — 

Account of, 24, 25. 

" Cement " {see " Cement"). 

Forest, 5. 

Flood-plain, 7. 

Gold, 12, 13, 14, 15, 27-47, 61, 69, 71. 

Gravels, 65, 69, 70, 71. 

Old channel of, 70. 

Quartz-grits, 61. 



Tuapeka Series, 27^7. 

Age of, 35-36. 

Auriferous lodes of, 27-43. 

Chemical composition of the rocks of, 36. 

Economic geology of, 37-47. 

Historical account of, 27-28. 

Petrography of, 28-33. 

Progressive metamorphism of the rocks of, 
33-34. 

Structure of, 34-35. 

Unconformity above, 18. 
Tumatakuri {wild-irishman), 5. 
Tungsten, analyses for, 40, 45. 
Tungsten, mode of deposition, &c., of 46. 

See also Scheelite ; Wolfram. 
Tussock, 6. 
Tutu, 5. 



u. 



Ulrich, G. H. F., 2, 9, 10, 15, 38, 41, 44, 58. 
Unconformity, Kakanui - Kaikoura Systems, 17, 

29. 
Unconformity, Tuapeka-Waitahuna Series, 18, 20, 

34. 
Undulose extinction, &c., 30, 32 
Uplands, 21. 



Valley gravels, 71-72. 

Van Hise, C. R., 10. 

Veronica, 5. 

Verier Burn (Post Office Creek), 2, 25. 

Deep lead of, 68. 

Gravels of, 65, 67-69. 
Volcanic rocks, 19. 

Basic, Hyde to Macrae's, 43. 

Basic and alkaline at Dunedin, relation to gold 
in schist, 43. 

Basic and alkaline, connection with cinnabar 
lode, 45. 

Basic and alkaline, connection with copper 
lode, 44. 

Of the Waitahuna Series, 63-64. 
Von Ettingshausen, C. {see Ettingshausen, C. von). 



w. 



Waihola, nephelinite near. 63-64. 
Waipori — 

Cinnabar, 44. 

District, minerals, rocks, and lodes of, &c. 
8,9. 

District, reports concerning, 8-10, 27-28. 

Falls, 2, 4, 66. 

Flat, 38, 65, 66. 

Township of, 11. 

ScheeUte, 45. 

Schist, 28, 33. 
Waipori River — 

Account of, 24, 25. 

Deep leads, 65. 

Fault basin, 66. 

Fault-hne valley, 22. 

Flood-plain, 7. 

Fulton's lode, 40. 

Gravel, 19, 65-67. 

Lower beds, 35. 

Quartz-grits, 6.5-67. 

Water-supply, 14. 



79 



Waitahuna — 

Auriferous gravels at, 65, 71. 

Basalt near, 64. 

" Cement" at, 14, 48, 55-56, 60, 61. 

Cinnabar near, 44. 

Copper near, 9, 44. 

Population, 11. 

Previous work, 17. 

Quartz-grits, 60-63. 

Reports, 8-10, 27-28. 
Waitahuna Gully, workings, plan, 55. 
Waitahuna Heights — 

Account of, 21. 

Agriculture, 12. 

Drainage, 26. 

Elevated peneplain, 24. 

Thrust, 21, 22, 48, 49. 
Waitahuna River, 24. 
Waitahuna Series, 48-64. 

Auriferous conglomerate or " cement " of, 
48-60. 

Conditions of deposition of, 64. 

Subdivision of, 48. 

Volcanic rocks of, 63-64. 
Wanaka System, 17, 28, 29. 



Wangaloa, fossiliferous beds near, 62, 63. 

Waronui coal-mine, 62. 

Water, for electric power, 26, 65. 

Waters, D. B., 15, 42. 

Weasels, 3. 

Weatherstones (see Wetherstones). 

Webb, R. (miner), 37. 

Weka, 3. 

Wetherstones — 

"Cement" of, 13, 14, 48, 50, .53-54, 59, 60 
69, 71. 

Faulting at, 24, 49, 53, 55. 

Flat at, 25. 

Lode near, 41. 

Origin of name, 5 (footnote). 

Quartz-grits of, 61. 
Wheat, 6. • 
White-eye, 4. 
Wild-irishman, 5. 
Wolfram, 16, 40, 46. 
Wood, J. N. (Warden), 9. 
Woolshed Creek, 14. 
Woolshed diggings, discovery of, 12. 
Wren, 4. 



By Authority : Marcus F. Marks, Government Printer, Wellington. — 1918. 



[600/9/16 - 1494 



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